Road & Bridge Design Publications€¦ · Updated contact names of requestees to Engineer of Road...

Road & Bridge Design Publications

Monthly Update – May 2020

1

Revisions for the month of May are listed and displayed below and will be included in

projects submitted for the September letting. E-mail road related questions on these changes

to [email protected]. E-mail bridge related questions to

[email protected].

Standard Plan Distribution

The distribution letter explaining the changes and the inserts used to keep a hard copy of the

standard plan booklet up to date can be found at:

https://mdotjboss.state.mi.us/SpecProv/getDocumentById.htm?docGuid=463735f9-1af8-

4c78-adc3-07a16bfa03f7

The new standard plans have been placed on the website and the special detail index has been

updated for the distribution.

Special Details

R-28-J: Curb Ramp and Detectable Warning Details: Revised the term “Sidewalk Ramp” to

“Curb Ramp”.

R-60-J: Guardrail Types A, B, BD, T, TD, MGS-8, & MGS-8D: Eliminated the “**” note on

the Type MGS-8D (wood post) detail, as it does not apply.

Road Design Manual

3.08.01E: Design Exceptions/Variances: Revised the approving authority for design

exceptions from the Engineer of Design to the Engineer of Road Design or the Chief Structure

Design Engineer.

3.12D: 3R Freeway Underclearances: Revised the section to allow retaining existing vertical

under clearances without a design exception on 3R freeway projects when a pattern of high

load hits does not exist.

3.12G: Vertical Clearance Requirement Table: Added a note (designated by ***) to the table

regarding retaining the existing vertical clearances without a design exception on 3R freeway

projects when a pattern of high load hits does not exist. Revised to match FHWA policy

(2017 Michigan Division clarification) regarding retaining the existing controlling criteria on

3R freeway projects.

mailto:[email protected]

mailto:[email protected]

https://mdotjboss.state.mi.us/SpecProv/getDocumentById.htm?docGuid=463735f9-1af8-4c78-adc3-07a16bfa03f7

Road & Bridge Design Publications

Monthly Update – May 2020

2

6.04.02, 6.06.02, 6.08.02, 6.08.05: Revised the term “Sidewalk Ramp” to “Curb Ramp”.

14.11: Design Exceptions/Variances: Revised the approving authority for design exceptions

from the Engineer of Design to the Engineer of Road Design or the Chief Structure Design

Engineer.

Bridge Design Manual

7.01.04 F. (LRFD Only), 7.02.05 C. (LFD & LRFD),7.02.12(LFD & LRFD): Updated contact

name to Chief Structure Design Engineer.

7.01.06 B. (LRFD Only): Updated criteria to live load plus dynamic load allowance.

7.01.08 (LFD & LRFD): Added a note (designated by ***) to the table regarding retaining the

existing vertical clearances without a design exception on 3R freeway projects when a pattern

of high load hits does not exist. Revised to match FHWA policy (2017 Michigan Division

clarification) regarding retaining the existing controlling criteria on 3R freeway projects.

Updated contact names of requestees to Engineer of Road Design and Chief Structure Design

Engineer.

7.02.13 (LFD & LRFD): Updated contact person to Bridge Design Project Manager.

8.05 A3. (LRFD Only): Clarified note to utilize HL-93 loading.

12.02.01: Added vertical clearance information for 3R construction which is defined in

section 7.01.08.

12.08.01: Updated “The Plan Review Meeting”.

Updates to MDOT Cell Library, Bridge Auto Draw Program, etc., may be required in tandem

with some of this month's updates. Until such updates to automated tools can be made, it is

the designer's/detailer's responsibility to manually incorporate any necessary revisions to

notes and plan details to reflect these revisions.

Index to Special Details 5-27-2020

SPECIAL DETAIL

NUMBER

NUMBER OF

SHEETS TITLE CURRENT

DATE

21 2 GUARDRAIL AT INTERSECTIONS 4-9-18

24 8 GUARDRAIL ANCHORED IN BACKSLOPE TYPES 4B, 4T, & 4MGS-8 9-28-18

99 2 CHAIN LINK FENCE WITH WIRE ROPE 9-22-14

R-15-G 3 COVER K 7-26-19

R-27-F 1 BRIDGE APPROACH CURB & GUTTER (USING EXISTING CATCH BASIN) 10-14-19

*R-28-J 7 CURB RAMP AND DETECTABLE WARNING DETAILS 5-8-20

R-32-F 8 APPROACH CURB & GUTTER DOWNSPOUTS 12-16-19

R-32-SD 6 APPROACH CURB & GUTTER DOWNSPOUTS (FOR EXISTING RAILINGS) 11-14-19

R-33-G 2 CONCRETE VALLEY GUTTER AND URBAN FREEWAY CURB 8-14-19

R-53-A 22 TEMPORARY CONCRETE BARRIER LIMITED DEFLECTION 8-14-15

R-56-F 6 GUARDRAIL MEDIAN OBJECT PROTECTION 2-5-19

*R-60-J 17 GUARDRAIL TYPES A, B, BD, T, TD, MGS-8, & MGS-8D 5-14-20

R-62-H 4 GUARDRAIL APPROACH TERMINAL TYPE 2M 5-1-18

R-63-C 16 GUARDRAIL APPROACH TERMINAL TYPES 3B & 3T 2-5-19

R-66-E 4 GUARDRAIL DEPARTING TERMINAL TYPES B, T, & MGS 9-28-18

R-67-G 16 GUARDRAIL ANCHORAGE, BRIDGE, DETAILS 11-6-19

R-67-SD 7 GUARDRAIL ANCHORAGE, BRIDGE, DETAILS (FOR EXISTING RAILINGS) 11-13-19

R-72-D 6 GUARDRAIL LONG SPAN INSTALLATIONS 3-4-20

R-73-F 3 GUARDRAIL OVER BOX OR SLAB CULVERTS 8-1-19

R-126-I 5 PLACEMENT OF TEMPORARY CONCRETE & STEEL BARRIER 8-25-15

* Denotes New or Revised Special Detail to be included in projects for (beginning with) the September letting.

Note: Former Standard Plans IV-87, IV-89, IV-90, and IV-91 Series, used for building cast-in-place concrete head walls for elliptical and circular pipe culverts, are now being replaced with plans that detail each specific size. The Bureau of Bridges & Structures, Structure Design Section will provide special details for inclusion in construction plans for MDOT jobs. To assure prompt delivery, requests must be made in advance. Contact: [email protected]

Former Standard Plans IV-93 and IV-94 series have been replaced with precast concrete box & three-sided culverts as per the 2012 Standard Specifications for Construction.

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Index to Bridge Detail Sheets 5-27-2020

DETAIL NUMBER

NUMBEROF

SHEETS TITLE CURRENT

DATE

B-22-E 5 BRIDGE RAILING, THRIE BEAM RETROFIT (R4 TYPE RAILING) 10-23-19

B-23-F 6 BRIDGE RAILING, THRIE BEAM RETROFIT (OPEN PARAPET RAILING) 10-23-19

B-28-A 7 BRIDGE BARRIER RAILING, TYPE 7 1-27-20

B-29-A 8 BRIDGE BARRIER RAILING, TYPE 6 1-27-20

B-50-A 3 BRIDGE RAILING, CONCRETE BLOCK RETROFIT 10-15-19

B-101-G 2 DRAIN CASTING ASSEMBLEY DETAILS 7-26-18

EJ3AC 1 to 3 EXPANSION JOINT DETAILS 10-8-19

EJ4P 1 to 3 EXPANSION JOINT DETAILS 10-8-19

PC-1M 1 PRESTRESSED CONCRETE I-BEAM DETAILS 8-23-17

PC-2H 1 70" PRESTRESSED CONCRETE I-BEAM DETAILS 8-23-17

PC-4F 1 PRESTRESSED CONCRETE 1800 BEAM DETAILS 8-23-17

* Denotes New or Revised Special Detail to be included in projects for (beginning with) the September letting.

Note: Details EJ3AC & EJ4P are interactive, i.e. designers and detailers choose details based upon railing type and angle of crossing. Place all details appropriate for the project, structure specific information, and the Expansion Joint Device quantity on the sheet. The sheet shall then be added to the plans as a normal plan sheet.

Detail PC-1M, PC-2H and PC-4F shall have structure specific information and quantities added to the sheet. The sheet shall then be added to the plans as a normal plan sheet.

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A

A

A

MAXIMUM SIDE FLARE SLOPE

REDUCED TO ACCOMMODATE

FULL CURB HEIGHT MAY BE

** R

AMP

SIDEWALK

SIDE FLARE

SIDE FLARE

5' MI

N.

SIDEWALK

5' MIN.

SIDE FLARE

SIDE FLARE

** RAMP

(FLARED SIDES, TWO RAMPS SHOWN)

(SEE NOTES)

SLOPE

10% MAX.

(SEE NOTES)

SLOPE

10% MAX.

(SEE N

OTES)SLOPE10% MAX.

(SEE N

OTES)SLOPE10% MAX.

B.L.T.

W.K.P. 71

A

(SEE NOTES)

(SEE

NOTES)

R-28-J

A

A

OBSTRUCTION

PERMANENT

** R

AMP

5' MI

N.

SIDEWALK

SIDEWALK

(ROLLED SIDES)

ROLLED CURB

"NON-WALKING" AREA

(SEE

NOTES)

(SEE NOTES)

24" ACROSS FULL WIDTH

DETECTABLE WARNING SURFACE

(SEE NOTES)



(SEE NOTES)



* LANDING

5% - 7% (8.3% MAXIMUM). SEE NOTES.

** MAXIMUM RAMP CROSS SLOPE IS 2.0%, RUNNING SLOPE

* LANDING

SEE NOTES.

OF TRAVEL. LANDING MINIMUM DIMENSIONS 5' x 5'.

* MAXIMUM LANDING SLOPE IS 2.0% IN EACH DIRECTION

DEPARTMENT DIRECTOR MICHIGAN DEPARTMENT OF TRANSPORTATION

OF

SHEET

PLAN DATEF.H.W.A. APPROVALCHECKED BY:

DRAWN BY:

Michigan Department of Transportation

BUREAU OF DEVELOPMENT STANDARD PLAN FOR

APPROVED BY:

APPROVED BY:

Paul C. Ajegba

BY

PREPARED

DESIGN DIVISION

DIRECTOR, BUREAU OF FIELD SERVICES

DIRECTOR, BUREAU OF DEVELOPMENT

CURB RAMP TYPE R

CURB RAMP TYPE F

DETECTABLE WARNING DETAILS

CURB RAMP AND

5-8-2020

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72R-28-J

SECTION A-A

PAVEMENT

1" EXPANSION JOINT

GRADE BREAK

(8.3% MAXIMUM) SEE NOTES

RAMP SLOPE 5% - 7%

A SIDEWALK

5' MI

N.

SIDE FLARE

(ROLLED / FLARED SIDES)

** R

AMP

(SEE N

OTES)SLOPE10% MAX.

WALKING AREA

"NON-WALKING" AREA

A

(SEE

NOTES)

ROLLED CURB

(SEE NOTES)



2" MAX.24" ACROSS FULL WIDTH (SEE NOTES)


RAMP RUN

* LANDING

SHALL BE AS CALLED FOR ON THE PLANS

RAMP AND LANDING SLAB THICKNESSES

B1

B2

B3

D1

D2

D3

C1

C2

C3

C4

C5

C6

F1

F2

F3

F4

F5

F6

A B

CURB TYPE

1

1

ƒ

ƒ

1

1

1

1

1

1

1

1

•

ƒ

ƒ

ƒ

ƒ

ƒ

ƒ

•

•

•

•

•

•

•

•

•

•

•

•

•

ƒ

ƒ

•

•

STANDARD PLAN R-30-SERIES

FOR CURB TYPES SEE

OPENING

CURB RAMP

* LANDING

(INCHES)

RISE

MAXIMUM

WITH THE GUTTER PAN

PAVEMENT SHALL END FLUSH

(TYPICAL ALL RAMP TYPES)

*** 5.0% MAX.

A B

SECTION THROUGH CURB RAMP OPENING

MAXIMUM RISE B

NOT TO EXCEED

MATCH RAMP SLOPE



SEE NOTES.



MICHIGAN DEPARTMENT OF TRANSPORTATION

OF

SHEET

PLAN DATEF.H.W.A. APPROVAL


OF CURB

FLUSH WITH BACK

RAMP SHALL END

THE RAMP OPENING.

MAXIMUM COUNTER SLOPE ACROSS

CROSS SECTION TO PROVIDE 5.0%

*** TRANSITION ADJACENT GUTTER PAN

SEE STANDARD PLAN R-30-SERIES

AS IN ADJACENT CURB & GUTTER

LANE TIE AND REINFORCEMENT

5-8-2020


CURB RAMP AND

CURB RAMP TYPE RF

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(MEDIAN ISLAND)

5' MI

N.

(PARALLEL RAMP)

5' MI

N.

DO NOT USE IN AREAS WHERE PONDING MAY OCCUR

SIDEWALK

SIDEWALK

** RAMP

** R

AMP

"NON-WALKING" AREA

5' MI

N.

SIDEWALK

SIDEWALK

** RAMP

** R

AMP

"NON-WALKING" AREA

"NON-WALKING" AREA

73

MEDIAN WIDTH

(COMBINATION RAMP)

ROLLED CURB

(SEE

NOTES)

(SEE

NOTES)

(SEE NOTES)



(SEE NOTES)



R-28-J


OF

SHEET



* LANDING

* LANDING

DETECTABLE WARNING IS REQUIRED.

IS AT LEAST 6'-0". OTHERWISE NO

ACROSS FULL WIDTH IF MEDIAN WIDTH

DETECTABLE WARNING SURFACE 24"



SEE NOTES.



5-8-2020


CURB RAMP AND

CURB RAMP TYPE P

CURB RAMP TYPE C

CURB RAMP TYPE M

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74

** R

AMP** RAMP

ROLLED CURB

"NON-WALKING" AREA

(DEPRESSED CORNER)

24"

USE ONLY WHEN INDEPENDENT DIRECTIONAL RAMPS CAN NOT BE CONSTRUCTED FOR EACH CROSSING DIRECTION

SIDEWALK

** R

AMP** RAMP

SIDEWALK

( TANGENT DETECTABLE WARNING SHOWN )

"NON-WALKING" AREA

24"

( RADIAL DETECTABLE WARNING SHOWN )

FROM THE ENDS OF THE RADIUS. SEE NOTES

2" MAXIMUM DETECTABLE WARNING BORDER OFFSET MEASURED

FROM THE ENDS OF THE RADIUS. SEE NOTES

2" MAXIMUM DETECTABLE WARNING BORDER OFFSET MEASURED


OF

SHEET



R-28-J

* LANDING

* LANDING



SEE NOTES.



5-8-2020


CURB RAMP AND

CURB RAMP TYPE D

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75

SIDEWALK (TYP.)

RAILROAD CROSSING MATERIAL (TYP.)

6'

MI

N.*

15'

MA

X.*

WARNING ON RAILROAD CROSSING MATERIAL.

OF THE NEAREST RAIL. DO NOT PLACE DETECTABLE

6' MINIMUM AND 15' MAXIMUM FROM THE CENTERLINE

SO THAT THE EDGE NEAREST THE RAIL CROSSING IS

* THE DETECTABLE WARNING SURFACE SHALL BE LOCATED

SH

OU

LD

ER

SIDEWALK

DETECTABLE WARNING AT RAILROAD CROSSING

DETECTABLE WARNING AT FLUSH SHOULDER OR ROADWAY

24" ACROSS FULL WIDTH (SEE NOTES)


24" ACROSS FULL WIDTH (SEE NOTES)


(SEE NOTES)



2" OF SHOULDER

NEAREST EDGE WITHIN

R-28-J


OF

SHEET



PEDESTRIAN GATE (WHERE PROVIDED)

5-8-2020


CURB RAMP AND

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LEGEND

CROSSWALK MARKING

SLOPED SURFACE

"NON-WALKING" AREA

PAVEMENT

1" EXPANSION JOINT

SECTION B-B

* GRADE BREAK

76

( )

B

B

THE BOTTOM GRADE BREAK.

ON THE RAMP SURFACE AT

WARNING SHALL BE LOCATED

CURB, THE DETECTABLE

WITHIN 5' OF THE BACK OF

BOTTOM GRADE BREAK ARE

WHERE BOTH ENDS OF THE

(8.3% MAXIMUM) SEE NOTES

RAMP SLOPE 5% - 7%

(TYP.)

OF DRAINAGE INLET

PREFERRED LOCATION

5'

* GRADE BREAK (TYP)

BREAK

* GRADE

THE DIRECTION OF TRAVEL.

CURB RAMPS SHALL BE PERPENDICULAR TO

* GRADE BREAKS AT THE TOP AND BOTTOM OF

DETECTABLE WARNING

OF CURB

END FLUSH WITH BACK

APPROACH AREA SHALL

BOTTOM GRADE BREAK

2% (5.0% MAX.) SLOPE BEYOND

*** 5.0% MAX. (5.0% MAX.)

2%

SLOPE ACROSS THE RAMP OPENING.

SECTION TO PROVIDE 5.0% MAXIMUM COUNTER

*** TRANSITION ADJACENT GUTTER PAN CROSS

SEE SECTION B-B

BEYOND BOTTOM GRADE BREAK.

5.0% MAX. RUNNING SLOPE


OF

SHEET



R-28-J

RAMP RUN

SHALL BE AS CALLED FOR ON THE PLANS

RAMP AND LANDING SLAB THICKNESSES

THE RAMP.

EXTENDING THE WIDTH OF

24" DETECTABLE WARNING,

OPENING

CURB RAMP

DETAILS.

SEE SHEET 2 FOR CURB RAMP OPENING

5-8-2020


CURB RAMP AND

(GRADE BREAK OFFSET GREATER THAN 5')

CURB RAMP LOCATED IN RADIUS (TYPE R SHOWN)

CURB RAMP PERPENDICULAR TO RADIAL CURB (TYPE F SHOWN)

IS NOT SIGNIFICANT ON RADIUS)

BACK OF CURB. (DOME ORIENTATION

WARNING SHALL BE LOCATED AT THE

THE BACK OF CURB, THE DETECTABLE

GRADE BREAK IS MORE THAN 5' FROM

WHERE EITHER END OF THE BOTTOM

(TYP.)

OF DRAINAGE INLET

ALTERNATE LOCATION

(TYPE F AND TYPE RF SHOWN)

CURB RAMP PERPENDICULAR TO TANGENT CURB

(GRADE BREAK OFFSET LESS THAN 5')

CURB RAMP LOCATED IN RADIUS (TYPE R SHOWN)

CURB RAMP ORIENTATION

ARE NOT ALIGNED

USE WITH RADIAL CURB WHEN THE CROSSWALK AND CURB RAMP

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WITH THE ADJACENT CONCRETE.

THE TOP OF THE JOINT FILLER FOR ALL RAMP TYPES SHALL BE FLUSH

MUNICIPALITY.

SIDEWALK SNOW REMOVAL EQUIPMENT NORMALLY USED BY THE

RAMP WIDTH SHALL BE INCREASED, IF NECESSARY, TO ACCOMMODATE

24"

DOME ALIGNMENT


DOME SPACING0.2"

DOME SECTION

1.4"

TO

0.9"

OF BASE

50% TO 65% 1.6" - 2.4"

1.6" - 2.4"

0.65"

MI

N.

0.65"

MIN.

PERPENDICULAR (OR RADIAL) TO GRADE BREAK

ALIGNED IN DIRECTION OF TRAVEL AND

77

OF TRAVEL.

THE LONG DIMENSION IS PERPENDICULAR TO THE DOMINANT DIRECTION

GREATER THAN •". ELONGATED OPENINGS SHALL BE PLACED SO THAT

MANUFACTURER'S ADA COMPLIANT GRATE. OPENINGS SHALL NOT BE

STRUCTURES ARE LOCATED IN THE RAMP PATH OF TRAVEL, USE A

LOCATION OF THE DRAINAGE STRUCTURE. WHERE EXISTING DRAINAGE

THE LOCATION OF THE RAMP SHOULD TAKE PRECEDENCE OVER THE

DRAINAGE STRUCTURES SHOULD NOT BE PLACED IN LINE WITH RAMPS.

NOTES:

CROSSINGS.

SHALL ALSO BE PROVIDED AT MARKED AND/OR SIGNALIZED MID-BLOCK

WHERE THERE IS EXISTING OR PROPOSED SIDEWALK AND CURB. RAMPS

RAMPS SHALL BE PROVIDED AT ALL CORNERS OF AN INTERSECTION

ACROSS THE WALK.

SIDEWALK SHALL BE RAMPED WHERE THE DRIVEWAY CURB IS EXTENDED

BROOMING, TRANSVERSE TO THE RUNNING SLOPE.

SURFACE TEXTURE OF THE RAMP SHALL BE THAT OBTAINED BY A COARSE

TRAVEL.

RAMP BE IN ONLY ONE DIRECTION, PARALLEL TO THE DIRECTION OF

WHERE CONDITIONS PERMIT, IT IS DESIRABLE THAT THE SLOPE OF THE

CARE SHALL BE TAKEN TO ASSURE A UNIFORM GRADE ON THE RAMP.

SHIFTING OR HEAVING.

FIELD CUT UNITS CAST AND/OR ANCHORED IN THE PAVEMENT TO RESIST

DETECTABLE WARNING PLATES MUST BE INSTALLED USING FABRICATED OR

CURB THE OFFSET IS MEASURED FROM THE ENDS OF THE RADIUS.

THE EDGES OF THE DETECTABLE WARNING IS ALLOWABLE. FOR RADIAL

AREAS. A BORDER OFFSET NOT GREATER THAN 2" MEASURED ALONG

RAMP/PATH OPENING EXCLUDING CURBED OR FLARED CURB TRANSITION

DIRECTION OF RAMP/PATH TRAVEL AND THE FULL WIDTH OF THE

DETECTABLE WARNING SURFACE COVERAGE IS 24" MINIMUM IN THE

IN THE PUBLIC RIGHT OF WAY.

RECONSTRUCTION, OR ALTERATION OF STREETS, CURBS, OR SIDEWALKS

DETAILS SPECIFIED ON THIS PLAN APPLY TO ALL CONSTRUCTION,

R-28-J

FULL LENGTH OF THE RAMP.

THE CROSS SLOPE TRANSITION SHALL BE APPLIED UNIFORMLY OVER THE

SLOPE MAY BE TRANSITIONED TO MEET AN EXISTING ROADWAY GRADE.

EXCEED 2.0%. FOR ALTERATIONS TO EXISTING ROADWAYS, THE CROSS

FOR NEW ROADWAY CONSTRUCTION, THE RAMP CROSS SLOPE MAY NOT

UNIFORM TRAFFIC CONTROL DEVICES".

FOR MARKING APPLICATIONS ARE GIVEN IN THE "MICHIGAN MANUAL ON

AS TO STOP TRAFFIC SHORT OF RAMP CROSSINGS. SPECIFIC DETAILS

CROSSWALK AND STOP LINE MARKINGS, IF USED, SHALL BE SO LOCATED

4' x 4'.

REDUCED TO NOT LESS THAN 4' AND LANDINGS TO NOT LESS THAN

WHEN 5' MINIMUM WIDTHS ARE NOT PRACTICABLE, RAMP WIDTH MAY BE

TRANSITIONS.

OF RAMPS TO EXCEED 15 FEET IN LENGTH NOT INCLUDING LANDINGS OR

REFERENCE. HOWEVER, IT SHALL NOT REQUIRE ANY RAMP OR SERIES

THE MAXIMUM RUNNING SLOPE OF 8.3% IS RELATIVE TO A FLAT (0%)

PERPENDICULAR TO ITS OWN DIRECTION(S) OF TRAVEL.

INDEPENDENTLY MAINTAIN A CROSS SLOPE NOT GREATER THAN 2%

ROUTE CROSSING THROUGH OR INTERSECTING THE CURB RAMP MUST

LANDING. HOWEVER, ANY CONTINUOUS SIDEWALK OR PEDESTRIAN

CURB RAMPS WITH A RUNNING SLOPE 5% DO NOT REQUIRE A TOP


OF

SHEET



5-8-2020


CURB RAMP AND

DIRECTED BY THE ENGINEER.

CURB RAMPS ARE TO BE LOCATED AS SPECIFIED ON THE PLANS OR AS

ORDER TO AVOID SHARP CURB RETURNS AT RAMP OPENINGS.

WHERE THEY ARE NOT REQUIRED, FLARED SIDES CAN BE CONSIDERED IN

LANDSCAPING, UNPAVED SURFACE OR PERMANENT FIXED OBJECTS.

SIDES ARE NOT REQUIRED WHERE THE RAMP IS BORDERED BY

CIRCULATION PATH LATERALLY CROSSES THE CURB RAMP. FLARED

ROADSIDE CURB LINE, SHALL BE PROVIDED WHERE AN UNOBSTRUCTED

FLARED SIDES WITH A SLOPE OF 10% MAXIMUM, MEASURED ALONG THE

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WOOD POST STEEL POST ELEVATION SHOWING POST SPACING

GUARDRAIL, TYPE A

ELEVATION SHOWING POST SPACING

GUARDRAIL, TYPE B

( WOOD POST )

22"

GROUND LINE

(TYP.)

SPLICE BOLT

6"

7"

6'-0"

3'-7"

WOOD LINE POST

6" x 8"

22"

(TYP.)

SPLICE BOLT

7"

6'-0"

3'-7"

UNDER NUT

ROUND WASHER

POST BOLT WITH

8"

UNDER NUT

ROUND WASHER

POST BOLT WITH

GROUND LINE

AND TYPICAL POST SPACING

EFFECTIVE BEAM ELEMENT LENGTH

12'-6"

* 28"

* SEE NOTES FOR GUARDRAIL IN CONJUNCTION WITH CURB

GROUND LINEOPTIONAL


GROUND LINE

* 2

8"

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE

POST SPACING

6'-3" TYPICAL6" x 8" WOOD LINE POST

LINE

GROUND

HINGE POINT

SHOULDER

WASHER UNDER NUT

POST BOLT WITH ROUND

COATED NAIL

3" LONG HOT-DIP ZINC

WOOD POST WITH A MINIMUM

TOE NAIL WOOD BLOCK TO

SHOULDER

NORMAL

2'-0"

8"8"(TYP.)

SPLICE BOLT

14"

7"

22"

3'-7"

6'-0"

** 5'-0" OR AS SPECIFIED ON PLANS

** FOR PAVED SHOULDER WIDTHS OF AT LEAST 12', USE 3'-0".

B.L.T.

W.K.P. 1 17R-60-J

STEEL LINE POST

W6 x 9 OR W6 x 8.5

MGS-8, & MGS-8D

TYPES A, B, BD, T, TD,

GUARDRAIL,

DEPARTMENT DIRECTOR MICHIGAN DEPARTMENT OF TRANSPORTATION

OF

SHEET

PLAN DATEF.H.W.A. APPROVALCHECKED BY:

DRAWN BY:

Michigan Department of Transportation


APPROVED BY:

APPROVED BY:

Paul C. Ajegba

BY

PREPARED

DESIGN DIVISION

DIRECTOR, BUREAU OF FIELD SERVICES

DIRECTOR, BUREAU OF DEVELOPMENT

5-14-2020


GUARDRAIL, TYPE BD

( WOOD POST )

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE

POST SPACING

6'-3" TYPICAL

* 28"

GROUND LINE


6" x 8" WOOD LINE POST

GROUND LINE

WOOD OFFSET BLOCK

6" x 8"

WASHER UNDER NUT


8" 8" 8"(TYP.)

SPLICE BOLT

14"

7"

6'-0"

22"

3'-7"

NAIL

HOT-DIP ZINC COATED

A MINIMUM 3" LONG

TO WOOD POST WITH

TOE NAIL WOOD BLOCK


GUARDRAIL, TYPE B (OR BD)

( STEEL POST )

GROUND LINE

* 2

8"

POST SPACING

6'-3" TYPICAL

22"

(TYP.)

SPLICE BOLT

7"

6'-0"

3'-7"

14"

GROUND LINE

UNDER NUT

ROUND WASHER

POST BOLT WITH

FOR STEEL POST

WOOD OFFSET BLOCK

ROUTED 6" x 8"

BEAM ELEMENT

POST BOLT

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE


172R-60-J

STEEL LINE POST

W6 x 9 OR W6 x 8.5

NUT

ROUND WASHER

FOR STEEL POST

ROUTED 6" x 8" WOOD BLOCK

STEEL LINE POST

W6 x 9 OR W6 x 8.5

(OPTIONAL)

GALVANIZING HOLE

2" TO 3"

MGS-8, & MGS-8D


GUARDRAIL,


OF

SHEET



5-14-2020

TOP

SIDEFRONT

WOOD OFFSET BLOCKS FOR GUARDRAIL, TYPE B AND TYPE BD

FOR USE ON WOOD POSTS

TOP

FRONT SIDE

FOR USE ON STEEL POSTS

WOOD POST STEEL POST

BEAM ELEMENT SPLICE DETAILS

1'-0•"

2"2" 4‚"4‚"

1„"

\ STEEL POST

POST BOLT SLOT

ƒ" x 2•"

\ POST BOLT SLOT

(TYP.)

SPLICE BOLT SLOT

x 1„"

1'-0•"

2"2" 4‚"4‚"

POST BOLT SLOT

ƒ" x 2•"

(TYP.)

SPLICE BOLT SLOT

x 1„"

\ WOOD POST

\ POST BOLT SLOT AND

3"

14"

7"

7"

1„"

ƒ" DIA. HOLE

+ „"-

\

14"

7"

7"

ƒ" DIA. HOLE

(SEE NOTES ON SHEET 16 OF 16)

173


OF

SHEET



R-60-J

8"

…"

6"

4‚" 3"3"8"

6"

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020


GUARDRAIL, TYPE T

( WOOD POST )


GUARDRAIL, TYPE TD

( WOOD POST )


GROUND LINE

* 34"

POST SPACING

6'-3" TYPICAL

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE


HINGE POINT

SHOULDER

LINE

GROUND

WASHER UNDER NUT


2'-0"

8"8"(TYP.)

SPLICE BOLT

SHOULDER

NORMAL

7‰

"28"

7'-0"

4'-0

Ž"

22"

7†

"

22"

(TYP.)

SPLICE BOLT

7'-0"

4'-0

Ž"

8" 8"

7†

"

WASHER UNDER NUT



28"

7‰

"

8"

OFFSET BLOCK

6" x 8" WOOD

GROUND LINE

GROUND LINE

* 3

4"

POST SPACING

6'-3" TYPICAL

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE




174


OF

SHEET



R-60-J

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020


GUARDRAIL, TYPE T OR TD

( STEEL POST )

BLOCK AND POST CONNECTION DETAILS

GUARDRAIL, TYPE B

GUARDRAIL, TYPE T

GUARDRAIL, TYPE B

GUARDRAIL, TYPE T

22"

(TYP.)

SPLICE BOLT

7'-0"

4'-0

Ž"

7†

"

28"

7‰

"

GROUND LINEFOR STEEL POST

WOOD OFFSET BLOCK

ROUTED 6" x 8" UNDER NUT

ROUND WASHER

POST BOLT WITH

BEAM ELEMENT

POST BOLT (TYP.)

NUT (TYP.)

(TYP.)

ROUND WASHER

GROUND LINE

* 34"

POST SPACING

6'-3" TYPICAL

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE


TO WOOD OFFSET BLOCK

CONNECTING STEEL POST

POST BOLT

ROUTED WOOD OFFSET BLOCK

CONNECTING STEEL POST TO

POST BOLT




POST BOLT


CONNECTING STEEL POST

POST BOLT


175


OF

SHEET



R-60-J

STEEL LINE POST

W6 x 9 OR W6 x 8.5

FOR STEEL POST


(OPTIONAL)

GALVANIZING HOLE

2" TO 3"

STEEL LINE POST

W6 x 9 OR W6 x 8.5

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020

TOP

SIDEFRONT

WOOD OFFSET BLOCKS FOR GUARDRAIL, TYPE T AND TYPE TD


TOP

FRONT SIDE



THRIE BEAM ELEMENT SPLICE DETAILS

1'-0•"

2"2" 4‚"4‚"

1„"

\ STEEL POST

POST BOLT SLOT

ƒ" x 2•"

\ POST BOLT SLOT

(TYP.)

SPLICE BOLT SLOT

x 1„"

1'-0•"

2"2" 4‚"4‚"

POST BOLT SLOT

ƒ" x 2•"

(TYP.)

SPLICE BOLT SLOT

x 1„"

\ WOOD POST

\ POST BOLT SLOT AND

3"3"

8"

8"

…"

6"6"

4‚"

3"2

2"

1„"

ƒ" DIA. HOLE

+ „"-

\

ƒ" DIA. HOLE

7‰

"7

‰"

7†

"

22"

7‰

"7

‰"

7†

"


176


OF

SHEET



R-60-J

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020

( WOOD POST )


LINE

GROUND

HINGE POINT

SHOULDER

WASHER UNDER NUT


COATED NAIL

3" LONG HOT-DIP ZINC

WOOD POST WITH A MINIMUM

TOE NAIL WOOD BLOCK TO

SHOULDER

NORMAL

2'-8"

8"

14"

7"

25"

3'-4"




8"

14"

7"

25"

3'-4"

6'-0"

WASHER UNDER NUT


NAIL

HOT-DIP ZINC COATED

A MINIMUM 3" LONG

TO WOOD POST WITH

TOE NAIL WOOD BLOCK

GROUND LINE

GUARDRAIL, TYPE MGS-8D

( WOOD POST )

8"

8"8"

GUARDRAIL, TYPE MGS-8

177


OF

SHEET



R-60-J

6'-0"

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020

( STEEL POST )

25"

7"

6'-0"

3'-4"

14"

UNDER NUT

ROUND WASHER

POST BOLT WITH

NUT

ROUND WASHER

BEAM ELEMENT

POST BOLT

GROUND LINE

FOR STEEL POST

WOOD OFFSET BLOCK

ROUTED 6" x 8"

FOR STEEL POST


STEEL LINE POST

W6 x 9 OR W6 x 8.5

STEEL LINE POST

W6 x 9 OR W6 x 8.5

GUARDRAIL, TYPE MGS-8 (OR MGS-8D)

178


OF

SHEET



R-60-J

(OPTIONAL)

GALVANIZING HOLE

2" TO 3"

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020



POST BOLT



CONNECTING WOOD POST

POST BOLT

1„"

\ STEEL POST

BLOCK AND POST CONNECTION DETAILS

TOP

SIDEFRONT


TOP

FRONT SIDE


3"3"

…"

6"6"

4‚"

3"

14"

7"

7"

1„"

ƒ" DIA. HOLE

+ „"-

\

14"

7"

7"

ƒ" DIA. HOLE

WOOD OFFSET BLOCKS FOR GUARDRAIL, TYPE MGS-8 AND TYPE MGS-8D

8

8"

179


OF

SHEET



R-60-J


MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020

6'-3" TYPICAL POST SPACING

12'-6" EFFECTIVE BEAM ELEMENT LENGTH

GROUND LINE

* 31"

TOP OF RAIL


28"

31"

GROUND LINE

34"

GROUND LINE

31"

30"

\ MGS POST

\ MGS POST

TYPE 1B, 2B OR 3B

APPROACH TERMINAL

OR GUARDRAIL

GUARDRAIL, TYPE BD

GUARDRAIL, TYPE B

1710


OF

SHEET



R-60-J

DETAIL A1, T1, T4, OR T6

GUARDRAIL ANCHORAGE, BRIDGE

GUARDRAIL ANCHORAGE, MEDIAN

GUARDRAIL, TYPE TD

GUARDRAIL, TYPE T

GUARDRAIL, TYPE MGS-8 OR MGS-8D

ELEVATION SHOWING POST SPACING FOR



MGS-8, & MGS-8D


GUARDRAIL,

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE

BEAM ELEMENT LENGTH

9'-4•" EFFECTIVE

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE

34'-4•" HEIGHT TRANSITION

W-BEAM ELEMENT

STANDARD (12'-6")

BEAM ELEMENT

MGS (9'-4•")

W-BEAM ELEMENT

STANDARD (12'-6")

BEAM ELEMENT LENGTH

9'-4•" EFFECTIVE

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE


LENGTH

EFFECTIVE

6'-3"

W-BEAM ELEMENT

STANDARD (12'-6")

BEAM ELEMENT

MGS (9'-4•")

POST SPACING

6'-3" TYPICAL

POST SPACING

6'-3" TYPICAL

GUARDRAIL APPROACH TERMINAL TYPE 1B, 2B, OR 3B

GUARDRAIL, TYPE B, GUARDRAIL, TYPE BD, OR

GUARDRAIL, TYPE MGS-8 OR MGS-8D TO

ELEVATION SHOWING TRANSITION DETAIL FOR CONNECTING

GUARDRAIL ANCHORAGE, BRIDGE DETAIL A1, T1, T4 OR T6

GUARDRAIL ANCHORAGE, MEDIAN,

GUARDRAIL, TYPE T, GUARDRAIL, TYPE TD,

GUARDRAIL, TYPE MGS-8 OR MGS-8D TO


\ GUARDRAIL POST

\ GUARDRAIL POST

TRANSITION

THRIE BEAM

SYMMETRICAL

5-14-2020


OF

SHEET



28"

31"

GROUND LINE

34"

GROUND LINE

31"

30"

\ MGS POST

\ MGS POST

1711R-60-J

MGS-8, & MGS-8D


GUARDRAIL,

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE

BEAM ELEMENT LENGTH

9'-4•" EFFECTIVE

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE


W-BEAM ELEMENT

STANDARD (12'-6")

BEAM ELEMENT

MGS (9'-4•")

W-BEAM ELEMENT

STANDARD (12'-6")

BEAM ELEMENT LENGTH

9'-4•" EFFECTIVE

BEAM ELEMENT LENGTH

12'-6" EFFECTIVE


LENGTH

EFFECTIVE

6'-3"

POST SPACING

6'-3" TYPICAL

POST SPACING

6'-3" TYPICAL

BEAM ELEMENT

MGS (9'-4•")

W-BEAM ELEMENT

STANDARD (12'-6")

TERMINAL TYPE 2M

GUARDRAIL APPROACH

TERMINAL TYPE 2M

GUARDRAIL APPROACH

GUARDRAIL APPROACH TERMINAL TYPE 2M

GUARDRAIL, TYPE B TO


GUARDRAIL APPROACH TERMINAL TYPE 2M

GUARDRAIL, TYPE T TO


GUARDRAIL, TYPE B

\ GUARDRAIL POST

GUARDRAIL, TYPE T

\ GUARDRAIL POST

TRANSITION

THRIE BEAM

SYMMETRICAL

5-14-2020

SECTION THROUGH BEAM ELEMENT

Œ"

1˜"

3‰" ˆ"

3‚"

-0 + „"

TOLERANCE

3‚

"

…" R

(TYP.)

1'-0‚

"

+

‰"

(TYP.)

•" R

SYMMETRICAL

ABOUT \

•" R

(TYP.) NE

UT

RA

L

AXI

S

1̂ "

10°

1712


OF

SHEET



R-60-J

BEAM ELEMENT SPLICE DETAILS

1'-0•"

2"2" 4‚"4‚"

(TYP.)

SPLICE BOLT SLOT

x 1„"

\ SLOTTED HOLE

SLOTTED HOLE

ƒ" x 2•"

MGS-8, & MGS-8D


GUARDRAIL,

4‚"4‚" 2"4‚"4‚"2"

3'-1•"

\ OF POST BOLT SLOTS

3'-1•" 3'-1•"

(TYP.)

SPLICE BOLT SLOT

ž" x 1„"

(TYP.)

POST BOLT SLOT

ƒ" x 2•"

10'-5"

FRONT ELEVATION OF BEAM ELEMENT

4‚"4‚" 2"

13'-6•"

4‚"4‚"2"

3'-1•"

\ OF POST BOLT SLOTS

3'-1•" 3'-1•" 3'-1•"

(TYP.)

SPLICE BOLT SLOT

ž" x 1„"

(TYP.)

POST BOLT SLOT

ƒ" x 2•"

FRONT ELEVATION OF MGS (9'-4•") BEAM ELEMENT

5-14-2020

SECTION THROUGH THRIE BEAM ELEMENT(FOR GUARDRAIL, TYPE T AND TD)

3‰" ˆ"

3‚"

-0 + „"

TOLERANCE

1˜"

3‚

"

Œ"

1„

"3‚

"

•" R

(TYP.)

1̂ "

10°

…" R

(TYP.)

(TYP.)

•" R

Œ"

1„

"3‚

"3‚

"

1'-8"

+

‰"

1713R-60-J


OF

SHEET



MGS-8, & MGS-8D


GUARDRAIL,

FRONT ELEVATION OF THRIE BEAM ELEMENT

4‚"4‚" 2"

13'-6•"

4‚"4‚"2"

> OF POST BOLT SLOTS

(TYP.)

SPLICE BOLT SLOT

ž" x 1„"

(TYP.)

POST BOLT SLOT

ƒ" x 2•"

3'-1•" 3'-1•" 3'-1•" 3'-1•"

5-14-2020

4‚"4‚" 2"4‚"4‚"2"

7'-3•"

3'-1•"

1'-8"

+

‰"

SPLICE BOLT SLOT (TYP.)

ž" x 1„"

POST BOLT SLOT (TYP.)

ƒ" x 2•"

4‚"4‚" 2"4‚"4‚"2"

7'-3•"

3'-1•"

+

‰"

1'-0‚

"

1'-8"

+

‰"


ƒ" x 2•"


x 1„"

1714


OF

SHEET



R-60-J

4‚"4‚"2" 4‚"4‚" 2"

7'-3•"

3'-1•"

1'-8"

<

‰"

<

‰"

1'-0‚

"

<

‰"

1'-0‚

"


ƒ" x 2•"


ž" x 1„"

ASYMMETRICAL THRIE BEAM TRANSITIONSNOTE: ASYMMETRICAL TRANSITION TYPE WILL VARY BY LOCATION DEPENDING ON GUARDRAIL LAYOUT

THRIE BEAM TRANSITION

SECTION THROUGH


SECTION THROUGH


SECTION THROUGH


SECTION THROUGH


SECTION THROUGH


SECTION THROUGH

MGS-8, & MGS-8D


GUARDRAIL,

SYMMETRICAL THRIE BEAM TRANSITIONS

3'-1•"

3'-1•"

3'-1•"

5•

"4‚

"

4‚

"5•

"

5-14-2020

TO GUARDRAIL, TYPE BD (OR TYPE TD)

DETAIL SHOWING TRANSITION FROM GUARDRAIL, TYPE B (OR TYPE T)

SPLICE BOLT AND POST BOLT

MINIMUM POST BOLT THREAD LENGTHAT BEAM ELEMENT SPLICE POSTS AND AT INTERMEDIATE POSTS

POST BOLTS, SPLICE BOLTS AND WASHERS

)

150'

METAL TAG

ROUND WASHER NUT

STANDARD WIDTH VARIABLE WIDTH (FIELD BEND)

8"

MA

X.

OF TRAFFIC

DIRECTION

OF TRAFFIC

DIRECTION

(TWO REQUIRED FOR TYPE TD)

(ONE REQUIRED FOR TYPE BD)

POST BOLT LENGTH 2'-10"

PAY ITEM: GUARDRAIL, TYPE BD (OR TD) GUARDRAIL, TYPE B (OR T)

PAY ITEM EACH SIDE:

APPROX. 6'-3"OFFSET BLOCKS (TYPE TD) 6" x 1'-0" x 1'-10"

OFFSET BLOCKS (TYPE BD) 6" x 1'-0" x 1'-3"

OFFSET BLOCKS (TYPE TD) 6" x 9" x 1'-10"

OFFSET BLOCKS (TYPE BD) 6" x 9" x 1'-3"

(TWO REQUIRED FOR TYPE TD)

(ONE REQUIRED FOR TYPE BD)

POST BOLT LENGTH 2'-4"

BOLT LENGTH MINIMUM THREAD LENGTH

18"

26•" 3"

9•" 1ƒ"

2•"

POSTBLOCK

OFFSET

POST BOLTS

NO. LENGTH

SPLICE BOLTS WASHERS

WOOD

WOOD

STEEL

STEEL

WOOD

STEEL

WOOD

STEEL

WOOD

STEEL

(ROUND)

NO

T

NE

ED

ED

AT I

NT

ER

ME

DI

AT

E

PO

ST

S

WOOD

WOOD

WOOD

WOOD

WOOD

WOOD

WOOD

WOOD

A

B

BD

T

TD

1

1

1

1

1

2

2

2

2

4

8

8

16

12

24

1

1

1

2

2

4

1

2

*

REQ'D (NO. REQ'D)(NO. REQ'D)

TYPE

GUARDRAIL

N/A

N/A

26•"

9•"

18"

2"

9•"

9•"

9•"

9•"

* 26•"

18"

(1‚" LONG)

EXTEND MORE THAN •" BEYOND NUT.

(OR TYPE T) TO GUARDRAIL, TYPE BD (OR TYPE TD). POST BOLTS SHALL NOT

* EXCEPT AS SPECIFIED ON DETAIL SHOWING TRANSITION FROM GUARDRAIL, TYPE B

AND 8 ON TYPE B END).

THRIE BEAM TRANSITIONS REQUIRE 20 SPLICE BOLTS EACH (12 0N TYPE T END

1‚" (SPLICE BOLT)

SEE CHART (POST BOLT)

1Š"

†"

“"Š"

•"

+ˆ

"

-

"

1„

"

†"

RECESS ONE OR BOTH SIDES

•" DIA. x ˆ" DEEP¤"1ƒ" DIAMETER

•" DIAMETER

1‚" •"

0.012" THICK

ƒ" DIA. HOLE

+ „

"

1•

" ƒ"

ƒ"

1" 3"

4" + „"

METAL TAG

EMBOSSED ƒ" HIGH ON THE

CURVED GUARDRAIL RADIUS

FOR CURVED GUARDRAIL WITH RADIUS OF 150' OR LESS 1715R-60-J


OF

SHEET



MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020

MINIMUM POST BOLT THREAD LENGTHAT BEAM ELEMENT SPLICE POSTS AND AT INTERMEDIATE POSTS

POST BOLTS, SPLICE BOLTS AND WASHERS

STANDARD WIDTH VARIABLE WIDTH (FIELD BEND)

8"

MA

X.

OF TRAFFIC

DIRECTION

OF TRAFFIC

DIRECTION

APPROX. 6'-3"

BOLT LENGTH MINIMUM THREAD LENGTH

18"

26•" 3"

9•" 1ƒ"

2•"

POSTBLOCK

OFFSET

POST BOLTS

NO. LENGTH

SPLICE BOLTS WASHERS

(ROUND)

REQ'D (NO. REQ'D)(NO. REQ'D)

TYPE

GUARDRAIL(1‚" LONG)

WOOD

STEEL

WOOD

WOOD

1

216

2

* 26•"

9•"MGS-8D

WOOD

STEEL

WOOD

WOOD

1

18

1

1

9•"

18"MGS-8

1716


OF

SHEET



R-60-J

PAY ITEM: GUARDRAIL, TYPE MGS-8D

GUARDRAIL, TYPE MGS-8 TO GUARDRAIL, TYPE MGS-8D

DETAIL SHOWING TRANSITION FROM

OFFSET BLOCKS (TYPE MGS-8D) 6" x 1'-0" x 1'-2"

OFFSET BLOCKS (TYPE MGS-8D) 6" x 9" x 1'-2"

2'-4" FOR TYPE MGS-8D

POST BOLT LENGTH

2'-10" FOR TYPE MGS-8D

POST BOLT LENGTH

GUARDRAIL, TYPE MGS-8

PAY ITEM EACH SIDE:

NUT.

TO GUARDRAIL, TYPE MGS-8D POST BOLTS SHALL NOT EXTEND MORE THAN •" BEYOND

* EXCEPT AS SPECIFIED ON DETAIL SHOWING TRANSITION FROM GUARDRAIL, TYPE MGS-8

ON TYPE MGS END).

THRIE BEAM TRANSITIONS REQUIRE 20 SPLICE BOLTS EACH (12 0N TYPE T END AND 8

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020

OF TRAFFIC

DIRECTION

PLACEMENT OF GUARDRAIL REFLECTORS

ONE-WAY TRAFFIC

TWO-WAY TRAFFIC

GUARDRAIL

NOTES GOVERNING THE USE OF GUARDRAIL REFLECTORS

GUARDRAIL REFLECTOR

DIRECTION OF RAIL LAP

TWO-WAY TRAFFIC

ONE-WAY TRAFFIC

3"

2"

ƒ"•

"

(TYP.)

REFLECTORIZED SIDE FACING TRAFFIC

13 GAGE GALVANIZED

(0.0934") NOMINAL

2ƒ"

5"

‚" R

1•

"96° + 4°

OF TRAFFIC

DIRECTION

OF TRAFFIC

DIRECTION

OF TRAFFIC

DIRECTION

OF TRAFFIC

DIRECTION

TRAFFIC

SURFACE FACING

REFLECTORIZED GUARDRAILSEE NOTES BELOW

OF TRAFFIC

DIRECTION

GUARDRAIL

SEE NOTES BELOW

ADJACENT GUARDRAIL POSTS

IN OPPOSITE DIRECTIONS ON

PLACE GUARDRAIL REFLECTORS

OF TRAFFIC

DIRECTION

OF TRAFFIC

DIRECTION

GUARDRAIL

HEIGHT AND COMPATIBILITY WITH POST HOLES.

THE POST BOLT HOLES SHALL BE LOCATED TO ENSURE PROPER RAIL

DEPTH OF THE BLOCK SHALL BE AS SPECIFIED ON THIS STANDARD AND

BEVELS SPECIFIED. THE LENGTH (FRONT AND BACK FACE), WIDTH AND

A 1" BEVELED TOP MAY BE USED IN LIEU OF WOOD BLOCKS WITHOUT

WOOD OFFSET BLOCKS WITH •" BEVELS AT THE TOP AND BOTTOM OR

HEIGHT.

THE POST BOLT HOLES SHALL BE LOCATED TO ENSURE PROPER RAIL

DEPTH OF THE POST SHALL BE AS SPECIFIED ON THIS STANDARD AND

WOOD POSTS WITHOUT BEVELS SPECIFIED. THE LENGTH, WIDTH AND

WOOD POSTS WITH •" BEVELS AT THE TOP MAY BE USED IN LIEU OF

BENT SECTION WILL BE REQUIRED FOR EACH CURVED ELEMENT.

150' OR LESS. A TAG IDENTIFYING THE CURVATURE OF THE SHOP

BEAM ELEMENTS SHALL BE SHOP BENT TO PLAN RADIUS FOR CURVE RADII

GUARDRAIL.

SHOULD BE MEASURED FROM THE GROUND JUST IN FRONT OF THE

THE GUARDRAIL PANEL IS LOCATED BEHIND THE CURB THE RAIL HEIGHT

CLOSEST TO THE EDGE OF THE TRAVELED LANE. WHEN THE FACE OF

GUTTER PAN, WHICH IS THE POINT ON THE GUTTER PAN THAT IS

THE RAIL HEIGHT SHOULD BE MEASURED FROM THE FRONT EDGE OF THE

WHEN THE FACE OF GUARDRAIL IS PLACED FLUSH WITH FACE OF CURB,

GUIDE TO STANDARDIZED HIGHWAY BARRIER HARDWARE."

AGC-ARTBA JOINT COMMITTEE, TASK FORCE 13 PUBLICATION TITLED "A

DETAILS SPECIFIED ON THIS STANDARD ARE ACCORDING TO THE AASHTO-

NOTES:

GUARDRAIL ANCHORAGE, BRIDGE.

GUARDRAIL DEPARTING TERMINALS AND STANDARD PLAN R-67-SERIES FOR

GUARDRAIL APPROACH TERMINALS, STANDARD PLAN R-66-SERIES FOR

SEE STANDARD PLAN R-61-SERIES, R-62-SERIES OR R-63-SERIES FOR

1717


OF

SHEET



R-60-J

BY THE ENGINEER.)

REASONABLY LEVEL BEYOND THE SHOULDER HINGE POINT, AS DETERMINED

EMBEDDED FOR ADDED STABILITY. (NOT NECESSARY WHEN THE SLOPE IS

PLAN, 8'-0" POSTS SHALL BE PROVIDED, WITH THE ADDITIONAL LENGTH

THE SHOULDER HINGE POINT, RATHER THAN AS SPECIFIED ON THIS

WHEN THE PLANS SPECIFY GUARDRAIL (TYPE B OR T) TO BE PLACED ON

REGARDLESS OF ROADWAY LIGHTING.

1. GUARDRAIL REFLECTORS SHALL BE USED ON ALL STANDARD GUARDRAIL RUNS,

b) 25'-0" ON CURVES WITH A RADIUS LESS THAN 1150'.

1150' OR MORE.

a) 5O'-0" ON TANGENT SECTIONS AND CURVES WITH A RADIUS OF

2. GUARDRAIL REFLECTORS ARE TO BE SPACED AT THE FOLLOWING INTERVALS:

APPROPRIATE GUARDRAIL APPROACH TERMINAL STANDARD PLAN.

3. FOR GUARDRAIL REFLECTOR PLACEMENT ON APPROACH TERMINALS, SEE THE

GUARDRAIL DEPARTING TERMINAL.

4. A GUARDRAIL REFLECTOR IS TO BE PLACED ON THE SECOND POST FROM THE

PLACED ON THE UPPER POST BOLT.

5. ON GUARDRAIL, TYPE T AND TYPE TD GUARDRAIL REFLECTORS ARE TO BE

6. GUARDRAIL REFLECTORS SHALL MATCH COLOR OF EDGE LINE.

BY THE ENGINEER.)

REASONABLY LEVEL BEYOND THE SHOULDER HINGE POINT, AS DETERMINED

EMBEDDED FOR ADDED STABILITY. (NOT NECESSARY WHEN THE SLOPE IS

9'-0" POSTS SHALL BE PROVIDED, WITH THE ADDITIONAL LENGTH

SHOULDER HINGE POINT, RATHER THAN AS SPECIFIED ON THIS PLAN,

WHEN THE PLANS SPECIFY GUARDRAIL TYPE MGS-8 TO BE PLACED ON THE

MGS-8, & MGS-8D


GUARDRAIL,

5-14-2020

MICHIGAN DESIGN MANUALROAD DESIGN

3.08

3R, 4R AND OTHER PROJECTS

3.08.01 (revised 5-27-2020)

General

A. (3R) Resurfacing Restoration and Rehabilitation

This work is defined in 23 CFR (Code of Federal Regulations) as "work undertaken to extend the service life of an existing highway and enhance highway safety. This includes placement of additional surface material and/or other work necessary to return an existing roadway, including shoulders, bridges, the roadside and appurtenances to a condition of structural or functional adequacy. This work may include upgrading of geometric features, such as widening, flattening curves or improving sight distances." Examples of this type of work include:

1. Resurfacing, milling or profiling, concrete overlays and inlays (without removing subbase).

2. Lane and/or shoulder widening (no increase in number of through lanes).

3. Roadway base correction.

4. Minor alignment improvements.

5. Roadside safety improvements.

6. Signing, pavement marking and traffic signals.

7. Intersection and railroad crossing upgrades.

8. Pavement joint repair.

9. Crush and shape and resurfacing.

10. Rubblize and resurface.

3.08.01A (continued)

11. Intermittent grade modifications (used to correct deficiencies in the vertical alignment by changing the paving profile for short distances) that leave the existing pavement in service for more than 50% of the total project length.

12. Passing relief lanes.

See Chapter 12 of the Bridge Design Manual for examples of “bridge” 3R work.

B. (4R) New Construction/ Reconstruction

Projects that are mainly comprised of the following types of work are not considered 3R.

1. Complete removal and replacement of pavement (including subbase).

2. Major alignment improvements.

3. Adding lanes for through traffic.

4. New roadways and /or bridges.

5. Complete bridge deck or superstructure replacement.

6. Intermittent grade modifications (used to correct deficiencies in the vertical alignment by changing the paving profile for short distances) that leave the existing pavement in service for less than 50% of the total project length.

The above lists are not all inclusive, but are intended to give typical examples of 3R and 4R work.


3.08.01 (continued)

General

E. Design Exceptions / Variances

The sections to follow include standards for geometric design elements for the various classifications of roadways and work types. For specific controlling geometric design elements, a formal design exception must be submitted and approved when the standards cannot be met. Other specific elements and conditions will require a less formal design variance when standards cannot be met.

3.08.01 (continued)

During the review process the Geometric Design Unit will review plans and identify the need for Design Exceptions (DE) or Design Variances (DV) when standards are not met for specified geometric design elements. These elements are listed below with their corresponding level of documentation and/or approval.

Non-Standard Design Element (NHS and Non-NHS) (See Section 3.11.01 for DE Criteria for 3R freeway work)

Applicability of Design Exception (DE) Design Variance (DV)

Design Speed

≥ 50 MPH < 50 MPH

Design Speed < Posted Speed DE DE

Lane Width* DE DV

Shoulder Width DE DV

Horizontal Curve Radius* DE DV

Superelevation Rate* DE DV

Superelevation Transition* DV DV

Maximum Grade* DE DV

Stopping Sight Distance (Horizontal and Vertical)*

DE DV

Cross Slope DE DV

Vertical Clearance DE DE

Design Loading Structural Capacity DE DE

Ramp Acceleration / Deceleration Length* DV DV

*Values based on design speeds less than posted.

Design Exception (DE) - Design Exception requests are submitted on Form DE26 and require approval by the Engineer of Road Design or the Chief Structure Design Engineer. With the exception of low speed (< 50 mph) vertical clearance DE’s, subsequent FHWA approval is required for DE elements specifically designated for federal approval in the Project Specific Oversight Agreement (PSOA). Design exceptions should be addressed as early in the life of a design as possible, preferably during the scoping process.

Along with the justification for not meeting MDOT and/or AASHTO standards the design exception includes a crash analysis and the estimated total cost required to attain full standards compliance. See Section 14.11 for design exception submittal procedures.


3.11.03 (continued)

Safety Considerations

K. Clear Zones & Fixed Objects

The current clear zone criteria specified in Section 7.01.11 should be used when upgrading freeways. Obstacles within these limits should be shielded or removed. Obstacles beyond these limits, but within the recovery area, should be reviewed by the Geometrics Unit in the Design Division.

L. Culvert End Treatments

The ends of culverts located within the clear zone on projects programmed for upgrading shall be according to MDOT Drainage Manual, Section 5.3.5.

M. Bridges

See the Bridge Management Unit, Construction Field Services Division for FHWA conformance requirements.

3.12 (revised 5-27-2020)

UNDERCLEARANCES

A. 4R Freeway

Roadway 4R projects on the Freeway System must be designed to meet the current AASHTO vertical clearance requirement of 16'-0" (16'-3" is desired for future overlay of the road). Scoping of projects must include a determination of the most effective means of obtaining the vertical clearance standard. A cost/benefit analysis to determine how best to achieve the standard, either in full or with incremental progress needs to be prepared. The analysis should include the alternatives of obtaining all vertical clearances with the road project, a bridge project, or some combination of road and bridge work to meet the clearance requirements. In many cases it may not be possible to achieve the complete vertical clearance with the proposed road project. If the most efficient plan for meeting the vertical clearance requirement is incremental progress, a design exception will be required. The design exception should be submitted as soon as possible, preferably prior to the submittal of the call for projects. This assures that design is not started on projects that may not be approved. The following is the minimum information required to prepare a vertical clearance analysis. This information is also required if a design exception is submitted.

Preliminary grades for the bridge and approaches, the route under the structure, and ramps if appropriate.

Location of existing structure foundations related to the proposed grade changes.

Impact evaluation on existing drainage.

Evaluation of any other deficient geometric feature.


3.12A (continued)

UNDERCLEARANCES

Determination of ROW needs.

Impacts on Environment.

Cost estimates for alternatives to meet vertical clearances.

Proposed time frame when the remainder of vertical clearance will be achieved (rough estimate)

Accident analysis where appropriate.

Soils (cut and fill information) and ground water information.

Impact on local businesses and residences.

User costs, constructability, maintaining traffic scheme and maintenance cost.

B. 4R Arterials

On Roadway 4R projects on Arterial systems, where no work is scheduled for the bridges, the bridges are considered existing structures and can be retained if they meet the 14'-6" vertical clearance standard, therefore no design exception is required. The existing clearance must be retained. It must not be reduced. Although not required, an evaluation should be performed to determine how best to achieve the standard, either in full or with incremental progress. Obtaining incremental progress toward the vertical clearance requirement with the road 4R project could prevent other more costly construction with the next major bridge rehabilitation or replacement project.

C. 4R Collectors and Local Routes

Maintain existing vertical clearance and a minimum of 14'-6" (14'-9" is desired on 4R projects if possible.)

3.12 (continued)

D. 3R Freeway

If the existing vertical clearance is not reduced and a crash pattern involving high load hits does not exist on a 3R freeway project, the vertical clearance may be retained without a design exception. However, if the vertical clearance is reduced to a value less than the standard (table value), a design exception will be required. The format for the design exception does not require a detailed evaluation but should include the basis for the request and review of the accident history and high load hits for the structures in the immediate vicinity of the structure.

E. 3R Arterials

On roadway 3R projects on Arterial systems, the bridges are considered existing structures and can be retained if they meet the 14'-0" vertical clearance standard, therefore no design exception is required. The existing vertical underclearance must be retained. Although not required, an evaluation should be performed to determine how best to achieve the standard, either in full or with incremental progress. Obtaining incremental progress toward the vertical clearance requirement with the road 3R project could prevent other more costly construction with the next major bridge rehabilitation or replacement project.

A design exception is required to maintain the vertical clearance below 14'-0". The likelihood of obtaining design exceptions for reducing vertical clearance is extremely remote.

F. Preventive Maintenance

Project scope of work includes but is not limited to road work consisting of thin HMA overlays, pavement grinding, concrete joint repair, slurry seal (shoulders only), and seal coat (shoulders only). Maintain existing vertical clearance. No design exception is required.


3.12 (continued)

UNDERCLEARANCES

G. Vertical Clearance Requirement Table

The desired vertical bridge underclearance should be provided as indicated below. If the desired underclearance cannot be provided, then the minimum underclearance shall be met. Where it is considered not feasible to meet these minimums, a design exception shall be requested. See the vertical underclearance design exception matrix in this section and Section 12.02 of the Bridge Design Manual. Requests to further reduce the underclearance of structures with existing vertical clearance less than indicated in the chart below should be made only in exceptional cases.

VERTICAL CLEARANCE REQUIREMENT TABLE

Route Classification Under the Structure

All Construction (Desired)

New Construction (Min *)

Road 4R Construction (Min *)

Bridge 4R Construction (Min *)

3R Construction (Min *)

Freeways 16’-3” 16’-0” 16’-0” 16’-0” 16’-0” ***

NHS Arterials ( Local & Trunkline)

16’-3” 16’-0” Maintain Existing ** and 14'-6" Min

16’-0” Maintain Existing ** and 14'-0" Min

Non NHS Arterials (Local & Trunkline)

16’-3” 14’-6” Maintain Existing ** and 14'-6" Min

Maintain Existing ** and 14'-6" Min

Maintain Existing ** and 14'-0" Min

Collectors, Local Roads & Special Routes (1) 14’-9” 14’-6” Maintain Existing **

and 14'-6" MinMaintain Existing **

and 14'-6" MinMaintain Existing **

and 14'-0" Min

* Minimum vertical clearance must be maintained over complete usable shoulder width.

** Existing vertical clearances greater than or equal to the minimums shown may be retained without a design exception. Vertical

clearance reductions that fall below the minimums for new construction require a design exception.

*** Existing vertical clearances may be retained (or increased) without a design exception unless a pattern of high load hits exists.

Vertical clearance reductions below the standard (table value) require design exceptions.

Information on the NHS system can be obtained by contacting the Statewide Planning Section, Bureau of Transportation Planning or found on the MDOT Web site at: http://www.michigan.gov/mdot-nfc

(1) Special Routes are in highly urbanized areas (where little if any undeveloped land exist adjacent to the roadway) where an alternate route of 16'-0" is available or has been designated. Bridges located on Special Routes in Highly Urbanized Areas can be found on the MDOT website at: https://mdotjboss.state.mi.us/stdplan/getStandardPlanDocument.htm?docGuid=c7b8d687-0bcd-4ea6-a614-47736321799e

Ramps and roadways connecting a Special Route and a 16’-0” route require a vertical clearance minimum of 14’-6” (14’-9” desired). Ramps and roadways connecting two 16’-0” routes require a vertical clearance minimum of 16’-0” (16’-3” desired).

Pedestrian bridges are to provide 1’-0” more underclearance than that required for a vehicular bridge. For freeways (Interstate and non Interstate), including Special Route

Freeways, the desired underclearance shall be 17’-3” (17’-0” minimum).

A vertical clearance of 23’-0” is required for highway grade separations over railroads. Clearance signs are to be present for structures with underclearance 16’-0” or less (show dimensions 2” less than actual). See https://mdotjboss.state.mi.us/TSSD/tssdHome.htmfor additional information and guidelines.

For shared use paths (pedestrian and bicycle) the vertical clearance to obstructions, including overhead fencing, shall be a minimum of 8’-6” (10’-0” desired). However, vertical clearance may need to be greater to permit passage of maintenance and emergency vehicles. In undercrossings and tunnels, 10’-0” is desirable for vertical clearance. See AASHTO’s Guide for the Development of Bicycle Facilities.

MICHIGAN DESIGN MANUAL ROAD DESIGN

CHAPTER 6 SURFACING AND SHOULDERS INDEX (continued)

6.06.15 Minimum Curb and Gutter Grades

6.06.16 Curb and Gutter for Erosion Control

6.06.17 Concrete Curb Cap

6.06.18 Deleted

6.06.19 Driveway Openings

6.06.20 Curb and Gutter Adjacent to HMA Base Course

6.07 CONCRETE DIVIDER

6.08 SIDEWALK

6.08.01 Department Position on Sidewalk Construction

6.08.02 Thickness

6.08.03 Reinforcement

6.08.04 Earth Excavation for Sidewalk

6.08.05 Curb Ramps A. Warrants for Curb Ramps and Curb Ramp Upgrade B. Scoping Considerations C. Design Standards D. Meeting Existing Sidewalk Grades and Elevations E. Accessibility Constraints F. Driveways G. Curb Ramp Location H. Traffic and Pedestrian Signals

6.08.06 Building Entrances A. Building Access Alterations B. Historic Buildings and Districts


6.04

CONCRETE CONSTRUCTION

6.04.01

History of Concrete Paving in Michigan

The first mile of rural concrete pavement in the nation was located on Woodward Avenue between 6 and 7 Mile Roads. The 17'-8" wide pavement was built by the Wayne County Road Commission and completed in 1909.

The beginning of the state trunkline system can be traced to a law enacted in 1913. At the time, road building was largely HMA and water-bound macadam on the "Class A" roads close to cities; gravel and earth predominated everywhere else. Although records are sketchy, it appears that the first concrete paving project, let for contract by the state, was on Dixie Highway just north of Monroe, in 1918. The circumstances of this project are peculiar in that it appears that the original contract was let by the Monroe County Road Commission. The original contractor went bankrupt so the project was taken over by the Department, which let a new concrete paving contract.

6.04.02 (revised 5-27-2020)

Glossary of Terms

Aggregate interlock - Load transfer that occurs across a concrete fracture by virtue of the irregular nature of the fracture surfaces due to cracking around, rather than through, the aggregate particles. The faces must be held in close proximity to one another in order to develop aggregate interlock.

Base plate - The galvanized metal base of joint dowel baskets that last appeared on Standard Plan E-4-A-130E (October 1963) and on E-4-A-138. Its purpose was to prevent sand from working up into the joint (It was used prior to subbase stabilization).

6.04.02 (continued)

“Black and white job" - A non-technical term referring to a roadway having both HMA surfaced and concrete surfaced lanes.

Blow-up - The upheaval and sometimes spectacular shattering of a concrete pavement caused by hot weather expansion in combination with loss of room for expansion, infiltration of incompressibles, and loss of cross-section in the lower portion of the joint, with consequential reduction of compressive stability and compressive strength. Usually occurring at a joint, it may commence in the period when the pavement is 8 to 18 years old.

Bonded overlay - A concrete overlay of an existing pavement that is encouraged to chemically and physically bond to the underlying pavement surface. The existing surface must be thoroughly cleaned by milling, grinding, or sand or water blasting prior to resurfacing.

Bulkhead joint - The formed joint, either longitudinal or transverse, between two adjacent concrete slabs, created when one slab is cast up against another already hardened slab.

Cold joint - The division between two concrete pours, one of which has begun to set before the other is cast against it. This disparity prevents the mixture from forming a continuous uniformly consolidated mass and may lead to separation of the concrete along this same line of division at sometime in the future.

Composite pavement - A portland cement concrete pavement with an HMA overlay


6.04.02 (continued)

Glossary of Terms

Concrete base course - A concrete pavement slab intended to be overlaid with a surface course, usually an HMA surface course. Hence, more tolerance in the surface finish is acceptable, joints are not separately sealed, etc.

Concrete pavement - As normally used in the Department, a term referring to a pavement on which the portland cement concrete is the riding surface, as distinguished from concrete base course.

Continuously Reinforced Concrete Pavement (CRCP) - Concrete pavement which contains substantial steel reinforcement. Steel reinforcement (commonly #4 or #5 bars) is placed in either the longitudinal direction or in both directions. CRCP pavement does not normally contain joints except at structures.

Contraction Joint - A joint in concrete pavement that serves as a plane of weakness joint. Movement in the slab due to contraction occurs here.

Crg Joint (Contraction-Reinforced-Grouted) - A contraction joint between an existing concrete pavement and a full depth concrete pavement repair. Epoxy coated load transfer bars are drilled and grouted in the existing pavement at the joint.

Curb-cut - A rounded reduction of curb height such as is encountered at a driveway or curb ramp.

6.04.02 (continued)

D-cracking - Deterioration along transverse or longitudinal pavement joints or cracks, caused by moisture absorption in the concrete coarse aggregate near the joint, with cracking occurring during subsequent cycles of freezing and thawing. This type of cracking takes its name from the characteristic concentric semicircular (as viewed in the vertical plane) hairline cracks that appear as parallel lines on the surface. These cracks often contain calcium hydroxide residue causing a dark surface stain. The deterioration progresses to a series of parallel cracks adjacent to the joint and eventually to disintegration and spalling, under traffic, 1’ to 2’ away from the joint.

Dowel basket - See "Load Transfer Assembly”

Dowel Bar Inserter - A machine that inserts load transfer dowels directly into the plastic concrete at contraction joints, eliminating the need for dowel baskets.

Drilled-in anchor - A method for anchoring a bar into an existing concrete structure. The bars are inserted into a previously drilled hole and anchored by an epoxy grout.

Durability, specifically, freeze-thaw durability - A term applied to the coarse aggregate in concrete to indicate its ability to resist the action of freezing and thawing while in a moisture saturated condition. Until 1988, it was expressed in terms of "Durability Factor" (0 = poor to 100 = excellent). In 1988, durability values were changed to dilation (expansion, expressed in units of percent per 100 cycles of freezing and thawing), with values from 0.000% (excellent) to about 0.200% (poor, failure in 12 cycles). Dilation of 0.067% per 100 cycles is equal to a durability factor of 20, which was a minimum specification limit from 1976 to 1988. A value of 0.040% per 100 cycles relates to the former durability factor of 36, and is the current minimum for freeway pavements.


6.06

CURB AND GUTTER

6.06.01

References

Department Standard Plans

R-29-Series, “Driveway Openings & Approaches, and Concrete Sidewalk”

R-30-Series, “Concrete Curb and Concrete Curb & Gutter”

R-31-Series, “Integral Curb and Integral Curb & Gutter”

R-32-Series, “Approach Curb & Gutter, Downspouts (For Bridge Barrier on Rural Highways)”

R-33-Series, "Concrete Valley Gutter and Urban Freeway Curb”

R-38-Series, "Concrete Divider”

6.06.02 (revised 5-27-2020)

Glossary of Terms

Back of curb - The vertical plane of the curb, or curb and gutter, structure, farthest from the roadway.

Barrier curb - In Department usage, a curb having a near - vertical front face of over 6” in height. (See definition of mountable curb, below, and further discussion under Section 6.06.05.)

Curb cut - A rounded reduction of curb height such as is encountered for an opening at a driveway or curb ramp.

6.06.02 (continued)

Face of curb - The vertical plane of the curb structure closest to the roadway.

Face-to-face - The distance between the two front faces of curbs on opposite sides of the street, shown on plans as "f-f".

Gutter pan - The horizontal portion of curb and gutter, i.e., that portion of the curb and gutter structure exclusive of the curb.

Integral curb - (Or integral curb and gutter) - The condition when the curb or curb and gutter is cast monolithically with the concrete pavement structure. When so constructed, there is obviously no visible joint line defining a gutterpan width and so it is impossible, by observation, to determine the nominal width, if any, of the gutter pan.

Mountable curb - In Department usage, a low curb height or having a low sloping or rounded face such as to allow a vehicle to drive over rather easily. (See definition of barrier curb, above, and further discussion under Section 6.06.05.)

Roll curb - (Or roll curb and gutter) - A mountable curb having a broadly rounded curb face that allows a vehicle driving over the curb rather easily.

Traffic control - The use of a linear structure, most often curb or curb and gutter, to visibly and physically define preferred points of ingress and egress to or from areas adjacent to the roadway.


6.08.02 (revised 5-27-2020)

Thickness

Concrete sidewalks are normally 4” thick. When part of a driveway, it should be constructed to the same thickness as the driveway approach, as detailed on Standard Plan R-29-Series. See Section 12.08.03D.

When it is determined at the Plan Review Meeting that there is evidence of trucks encroaching on curb returns at short-radius intersections or where the potential for encroachment will exist after project completion, the designer should call for 6” thick concrete for sidewalk and curb ramps within the return. This thickness can be increased if there is potential for very heavy trucks to encroach on the return.

6.08.03

Reinforcement

Sidewalks are usually not reinforced. Occasionally, a municipality will request the Department to reinforce sidewalk within its limits. If such reinforcing of sidewalk is standard municipal policy elsewhere, the sidewalk may be reinforced at project cost.

The plans should note that 6” x 6” mesh should be used, with either No. 10 wire weighing 21 pounds per 100 sft or No. 6 wire weighing, 42 pounds per 100 sft, whichever is the municipal standard.

6.08.04

Earth Excavation for Sidewalk

Any earth excavation and backfilling required for construction of sidewalk is included in the pay item for sidewalk.

6.08.05 (revised 5-27-2020)

Curb Ramps

Curb ramps are mandated by Act 8, P.A. of 1973 (amended by Act 35 in 1998), as was the issuance of Standard Plan R-28-Series, “Curb Ramp and Detectable Warning Details". FHWA guidance indicates that ramps be constructed whenever construction involves curb or sidewalk. On May 8, 1973, the Department extended this requirement, by policy to include resurfacing projects that did not ordinarily require the replacement of existing curb or sidewalk.

Federal mandates followed this State law in conjunction with the Americans with Disabilities Act of 1990. The United States Access Board published the Americans with Disabilities Act Accessibility Guidelines (ADAAG) in 1991 and subsequently extended its application to Public Rights of Way in 1994. The Access Board later published the Public Rights of Way Accessibility Guideline (PROWAG) to address accessibility issues specific to public rights of way.

It should be emphasized that there is little permitted reason for failure to place or upgrade a curb ramp on a road construction project if a sidewalk meets a curb in an obvious crosswalk situation. An "obvious crosswalk situation" would be where a sidewalk intersects with the roadway, whether or not there are painted crosswalk lines or a traffic signal present.


6.08.05 (continued)

Curb Ramps

A. Warrants for Curb Ramps and Curb Ramp Upgrade

Based on FHWA guidance, curb ramp construction and/or curb ramp upgrade be incorporated with new construction, and roadway alterations.

New Construction refers to the initial construction of a new roadway facility on a new alignment for which new right of way is acquired. Curb ramp installation is required and new construction standards are fully enforced.

Alteration refers to changes that affect or could affect the usability of an existing roadway facility. Curb ramp installation and upgrading is required prior to or at the time of a roadway alteration. New construction standards are applicable to the maximum extent practicable.

Maintenance refers to maintenance activities that do not affect the usability of an existing road. Curb ramp accessibility upgrades are not required to be performed in conjunction with maintenance treatments.

The U.S. Department of Justice and the FHWA issued a joint Technical Assistance memo in 2013 to clarify which roadway treatments fall within the definition of an alteration and which are considered maintenance.


Alterations include:

Reconstruction

Rehabilitation – including cold milling & resurfacing, slab replacement, slab jacking, widening, adding pavement structural capacity.

Open-Graded Surface Course (open graded friction course)

Micro-surfacing (includes rut filling)

Double Chip Seal

HMA Overlay (regardless of thickness)

Cape Seal - (Chip seal capped with a slurry seal, micro-surface or other treatment to fill voids in a chip seal).

In-Place Asphalt Recycling

Other condition requiring accessibility upgrading includes:

Altered crossings through driveways. See Section 6.08.05F for driveway applications.

Independent shared use path crossing are treated the same as sidewalks with regard to accessible roadway crossings.

Installation of pedestrian signals. See Section 6.08.05G.

Existing curb ramps without detectable warnings but otherwise compliant must be retrofitted with detectable warnings in conjunction with alterations to an existing roadway.



Curb Ramps

Maintenance includes:

Crack Filling and Sealing Surface Sealing (liquid sealant) Chip Seals Slurry Seals Fog Seals Scrub Sealing Joint Crack Seals Joint Repairs Dowel Retrofit Spot High Friction Treatments Diamond Grinding Pavement Patching

Other routine operations where curb ramp upgrades are not required include:

Signing, pavement marking projects.

Guardrail/Safety upgrade projects.

Landscape/Streetscape projects (except where an existing sidewalk or curb ramp is altered)

Independent Utility Work/Maintenance (except where an existing sidewalk or curb ramp is altered or when work is extensive such that an entire crosswalk is reconstructed)

Two or more maintenance treatments may be combined and still be considered a maintenance treatment. However, if more than one of those treatments contains aggregate and/or filler, the combination will be considered an alteration.

For example a cape seal is an integrated system comprised of two maintenance treatments, a chip seal and a slurry seal. The slurry seal includes aggregate and filler to fill the voids of the aggregate in the chip seal. They combine as an alteration.”

6.08.05 (continued)

B. Scoping Considerations

If the projects limits include only a portion of an intersection, all ramps within the intersection shall be evaluated for compliance and the project limits extended to include all ramps.

Smaller scale projects such as CPM may still require a right of way phase to accommodate consent to tie into existing sidewalk outside the right of way. See Section 5.05.02 for more information on right of way requirements.

Alteration projects will likely require accurate contour and elevation information prior to designing compliant curb ramps.

C. Design Standards

Standard Plan R-28-Series details the requirements for ramp width, cross slope, running slope, landings, curb transition, and detectable warning surfaces. Designers should investigate site conditions in order to determine and design the appropriate treatment for each curb ramp location. Where fully compliant curb ramps are impracticable, compliance is required to the maximum extent practicable. See Section 6.08.05E“Accessibility Constraints”. This will require preliminary field work in order to design for maximum practicable compliance.

The curb ramp types detailed on Standard Plan R-28-Series represent some of the more conventional applications. Existing conditions may require variations not shown on the standard. The designer may need to combine the features of two or more ramp types to provide a compliant design.


6.08.05C (continued)

Curb Ramps

There are several basic elements that should be incorporated into the design. These are:

1. Minimum width (5 ft.). The minimum width of 5 ft. allows side by side wheelchair passing and is consistent with most sidewalk widths. Sidewalks less than 5 ft. wide require a 5 ft. x 5 ft. wide passing space every 200 ft. or less. In order to accommodate unavoidable existing width restrictions the PROWAG allows a reduction to not less than 4 ft.

2. Maximum running slope (8.3%). The maximum running slope is absolute and therefore a target maximum of 5% to 7% is used to allow for construction inconsistencies. However, the running slope shall not require the ramp length to exceed 15 ft. (See Section 6.08.05D“Meeting Existing Sidewalk Grades and Elevations”).

3. Maximum cross slope (2%). The maximum cross slope is absolute for ramps at intersections except as stated below. Designers should use a target cross slope less than the maximum to account for inconsistencies in concrete finishing.

When resurfacing or reconstructing existing roadways, the ramp cross slope may be blended to meet existing steeper roadway grades. Significant redesign of an existing cross road to accommodate a ramp cross slope commonly exceeds the scope of a roadway alteration. The curb ramp cross slope should be transitioned through the full length of the ramp to minimize abrupt changes. If opportunities within the roadway construction scope of work are available to achieve even partial compliance, they should be pursued.


For new roadways, the cross slope of the cross walk must not exceed 2% at stop controlled (stop sign) crossings and 5% at signalized and uncontrolled crossings. The cross slope at mid-block crossings may follow the roadway grade.

4. Landing - 5’ x 5’ minimum, 2% max slope in the direction(s) of pedestrian travel. A landing is required at the top of perpendicular ramps. However, if the ramp running slope is less than 5%, it is considered a “blended transition” and does not require a landing. In order to accommodate unavoidable existing width restrictions the PROWAG allows a reduction to no less than 4’ x 4’.

5. Maximum Bottom Counter Slope - (5% and flush with no vertical lip to the ramp). The maximum counter slope is provided to minimize wheelchair front caster snagging at the bottom of the ramp.



Curb Ramps

6. Detectable Warning - Detectable warnings are truncated domes that serve as surface tactile cues to alert persons with sight disabilities of an upcoming change from pedestrian to vehicular way. The dimensions and location are detailed on Standard Plan R-28-Series.

They are not intended as a way finding device. Square dome alignment within the boundaries of the detectable warning is detailed on the standard plan. However, orientation of the detectable warning surface is relative to placement location. Although preferable, it is not always relative to the direction of travel. Radial alignment is acceptable to match a radial curb alignment.

Detectable warnings are required at the intersection of sidewalks at streets regardless of whether the sidewalk is ramped or flush to the street or shoulder.

In addition to roadway intersections, detectable warnings are also required at mid-block crossings, sidewalk/railroad crossings, and the intersection of sidewalks with controlled commercial driveways (see Section 6.08.05F).


7. Grade Break Orientation – The grade break at the curb ramp terminals (top or bottom) should be flush and perpendicular to the direction of travel on the ramp. The objective is to provide a square approach to and from the ramp. The bottom grade break is generally located at the back of curb line for perpendicular ramps. However, it can be located up to 5 ft. from one end of a radial curb line in order to maintain a perpendicular orientation (see Standard Plan R-28-Series).

8. Flared Curb Ramps - When a sidewalk or pedestrian circulation path laterally crosses the curb ramp, the sides of the curb ramp must be flared with a 10% maximum slope as shown in Standard Plan R-28-Series for Flared Curb Ramps.

9. Rolled Curb - When the side of the ramp borders a non-walking surface such as grass or landscaping or a permanent obstruction, a rolled curb is permitted on the side of the ramp. Rolled curb is not defined as vertical faced or by a specified radius but rather curb not limited by the 10% maximum defined for flared curb. It can be as flat or steep as needed.

10. Measurement and Payment - When determining Curb and Gutter, and Curb Ramp Measurements and Payments the following illustration represents the various elements of a curb ramp. It illustrates the breakdown of pay items and their limits of payment.

Any earth excavation and/or backfilling required to construct curb ramp will be included in the pay item for curb ramp, unless the contract documents specifically include separate pay items for this work.



Curb Ramps

Curb Ramp Measurement and Payment Illustration

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6.08.05 (continued)

Curb Ramps

D. Meeting Existing Sidewalk Grades and Elevations

Sidewalk grades generally tend to follow the grade of the bordering street. When the existing sidewalk grade is steep, it becomes more difficult to comply with the maximum curb ramp running slope of 8.3% without “chasing grade” to meet the existing sidewalk. In some cases it results in an infinite run. Excessive ramp runs might also result when the existing sidewalk is at a significantly higher elevation than the adjacent road.

When this occurs, the maximum running slope may be exceeded in order to limit the ramp length(s) to not more than 15 ft. measured from the ramp grade break. The need to exceed the maximum slope must be documented (See Section 6.08.05E). The 15 ft. limit on ramp length does not include the landing or transition slabs to tie into the existing sidewalk. Three examples are illustrated:

Unlike other maximum dimensions, the 15 ft. limit is not absolute. If compliance with the maximum running slope (8.3%) can be achieved by extending the ramp by one or two flags of sidewalk beyond the 15 ft. limit, it should be considered within practicable limits.

A landing is required at the top of perpendicular ramps. However, if the ramp running slope is less than 5%, it is considered a “blended transition” and does not require a landing.

6.08.05D (continued)


6.08.05 (continued)

Curb Ramps

E. Accessibility Constraints

When it is impracticable to meet all standard compliance elements, the standards must be met to the maximum extent practicable. Impracticability does not apply for new roadway construction.

A strict definition of “practicable” is not provided since the potential circumstances for each installation is limitless. Some circumstances of impracticability are clear such as impacts on structural integrity of surrounding features, or an inability to adapt to existing immovable or unalterable conditions. Other circumstances such as real estate limitations and historic preservation can also represent impracticabilities.

The curb ramp elements are not listed in any order of preference or importance. Order of importance may vary for each application. When it is impracticable to provide compliant elements, they should be provided to the maximum extent practicable.

While cost is not itself an acceptable argument for noncompliance, scope can be a prevailing factor. If certain significant efforts required to meet the standard are not otherwise called for in a project, it may be a impracticability. Examples would be utility relocation or the acquisition of right of way for a roadway alteration project. If utility relocation or right of way acquisition is not required in the project for any other reasons, then it is preferred but not required that the same efforts be made solely for ADA compliance. See Section 5.05.02 for more information on fee, easement and consent requirements for sidewalks.

6.08.05E (continued)

When full compliance is impracticable and compromises are necessary, consideration should be given to safe refuge for the pedestrian. Flush transitions and flatter bottom entrances or a marked refuge area in the pavement allows persons in wheelchairs to leave the vehicular way prior to negotiating possible steeper ramp grades or cross slopes that result from impracticability.

When determining the correct balance to provide maximum extent practicable, it is best to follow good engineering judgment. Compromises may be needed for more than one standard element. If full compliance is impracticable, strive for maximum overall improved accessibility. Do not over compensate to favor one element. Over emphasis on a single element may cause a reduction in overall accessibility in comparison to the original condition.

Accessibility constraints should always be documented in the project files using MDOT Form 0370. This is retained as justification to address possible future claims. The documentation should include location, non-compliant element(s), reason for impracticability and maximum extent practicable.


6.08.05 (continued)

Curb Ramps

F. Driveways

When project work alters a driveway that crosses a sidewalk or alters the sidewalk abutting a driveway, the crossing through that driveway must be ADA compliant. Sidewalks are normally continuous through residential driveways and don’t require either curb ramps or detectable warnings. However, commercial driveways with curbed returns may present a barrier that requires a curb ramp.

Detectable warnings at commercial driveways are only used when the crossing is signalized or stop controlled with a regulatory stop sign. When this level of traffic control is needed, the driveway presents more of a street-like encounter for persons with sight disabilities and therefore warrants detectable warnings. Otherwise only the curb ramp is required. Overuse of detectable warnings cause misinformation for persons with sight disabilities.

The path crossing through the driveway must meet the standards for sidewalks including width, slope and cross slope. If continuous sidewalk construction or reconstruction is not in the scope of work, a short transition may be required to meet the existing sidewalk cross section at either end of the driveway crossing.

6.08.05 (continued)

G. Curb Ramp Location

Federal Code 28 CFR, Part 36 states;

“4.7.1 Location. Curb Ramps complying with 4.7 shall be provided wherever an accessible route crosses a curb.”

As stated earlier in this section, there are few permitted reasons not to provide curb ramps where a sidewalk crosses a curb. The absence of signals or marked crossings is not sufficient justification to exclude a curb ramp.

However, there are some circumstances, both obvious and obscure, that may affect the determination of curb ramp need and location.

Absence of Sidewalk In most cases the absence of sidewalk, (existing or planned) coincides with exemption from the requirement to provide curb ramps. The ADA does not require the installation of ramps or curb ramps in the absence of a pedestrian walkway with a prepared surface for pedestrian use. The ADA also does not require the provision of sidewalk where none currently exists. However, certain circumstances may require some minimum treatment for a quadrant without sidewalk.

The installation or presence of a pedestrian signal (whether pedestrian activated or not) suggests implicit intent of pedestrian travel. Accessibility from the road to a pedestrian activated signal would be required despite the absence of sidewalk. This may include curb ramps and an accessible path to a level surface at the push button. Where signals are not pedestrian activated and sidewalks are not present, the vertical portion of any curb should be gapped to provide a minimum 5 ft. wide clear opening to the implied path. See Section 6.08.05H for information on Traffic and Pedestrian Signals.


6.08.05G (continued)

Curb Ramps

Evidence of Pedestrian Travel Where sidewalk is not provided or planned at either side of a street crossing but there is evidence of pedestrian travel (worn path), a curb ramp is not required. However, the vertical portion of any curb should be gapped to provide a minimum 5 ft. wide clear opening to the path.

Prohibited Crossings Where a sidewalk meets a road and pedestrian crossing is prohibited, a curb ramp is not required at either side of the road. The end of the sidewalk should be delineated by both visible and tactile cues. A sign should be provided prohibiting crossing for all pedestrians. The tactile cue must be either detectable by cane or foot. A barrier approximately six inches in height can be detected by cane. Since a barrier is not always practical or context sensitive, a planted or gravel strip between the end of the sidewalk and the curb can serve as a tactile indication of the end of the pedestrian path. The strip should have a minimum dimension of two feet in the direction of travel.

Detrimental Crossings As previously stated, the absence of cross walk markings or signals does not imply an exemption for the provision of curb ramps. However, even where crossing is not expressly prohibited but is clearly not intended, circumstances may make it prudent to exclude ramps leading to undesirable crossing points. As with prohibited crossings, it may be desirable to end the sidewalk by separating it from the curb with a planted or gravel strip to provide underfoot detection of the path’s end.

6.08.05G (continued)

Examples of undesirable crossing situations are at mid-block locations or three legged intersections where crossings may lead to or near driveways. Turning traffic from driveways may not expect pedestrians where a crossing is not clearly marked. The same may also be true where cross roads are slightly jogged across the mainline roadway. An unmarked crossing that is offset too far from an intersection may cause a hidden vehicle/pedestrian conflict.

Logical crossing opportunities should be selected at reasonable intervals that provide safer direct corner-to-corner crossing. It may be acceptable at times to direct pedestrians to a safer alternate quadrant or nearby intersection.

When evaluating crossing intent, high consideration should be given to providing ramped crossings to public service destinations such as public transit stops, schools, hospitals, libraries, post offices, etc.


6.08.05 (continued)

Curb Ramps

H. Traffic and Pedestrian Signals

While signal maintenance does not warrant a curb ramp upgrade, new signal installation might. Circumstances requiring curb ramp installation or upgrade in conjunction with signal installation include:

Alteration to existing sidewalk/curb ramp.

Absence of a curb ramp where a sidewalk is curbed at the street intersection.

Absence of a curb ramp where a crossing is served by a pedestrian signal (with or without sidewalk).

See Section 6.08.05G for signal accessibility in the absence of sidewalk.

Existing ramps may remain in place without upgrade if they are not otherwise altered by the signal work.

For roadway alteration projects without signal work, consideration should be made to improve accessibility to push button signals. If the curb ramp is to be upgraded, designers are encouraged to extend paving to provide access to pedestrian activated signals where access is not currently provided.

Curb ramp construction should not reduce the existing level of accessibility of the existing pedestrian signal.

ADA requirements for pedestrian push button signals are addressed separately in Traffic and Safety standards and guidelines. ADA requirements for signal upgrading apply in conjunction with alterations to external components of the signal. Sidewalk or curb ramp construction alone does not activate a requirement to upgrade the signal.


14.10 (continued)

SCOPE VERIFICATION MEETING

NOTE: At this stage, the Project Manager should check to see if the project is required to be on the STIP (Statewide Transportation Improvement Plan). This may be done by accessing: JobNet

Job/CR Search (enter job number) Approved Job

S/TIP

The S/TIP Indicator shows if the project is required to be on the STIP or TIP. The Phase tab in JobNet shows the S/TIP Cycle each phase is proposed for and the status. Project Managers needing clarification concerning the status of the STIP should contact the Region Planner or Statewide Planning Section of the Statewide Transportation Planning Division in the Bureau of Transportation Planning.

14.11 (revised 5-27-2020)

DESIGN EXCEPTIONS / VARIANCES

After the scope verification meeting is held and the project scope has been agreed upon, the Project Manager should identify any Design Exceptions or Variances (DE or DV) to MDOT standards that will be utilized in the design of the project (See Section 3.08.01E). Exceptions and Variances to MDOT design standards should be identified, and, ideally, completed during the scoping process. However, if this has not been done, a Design Exception Request (Form DE26) or Design Variance (Form DV26) should be completed. The Project Manager should consult with the Geometrics Unit of the Design Division when identifying and developing justification for design exceptions or variances. Previously completed Design Exceptions / Variances should also be reviewed for accuracy and revised at this time.

The Project Manager should request that Design Exception/Variance folders be created in ProjectWise under the project number by e-mailing [email protected] with a link to the project or by providing the TSC and the Job Number. Consultant access to ProjectWise should also be requested at this time, if necessary. Two DE folders (MDOT and PoDI) and one DV folder will be created for each project, based on possible oversight type of Design Exception or Variance. The folders will be located under “Supporting Documents” and “Design Exception” or “Design Variance”. For each design exception/variance submitted, the Project Manager should place a single Adobe (.pdf) file (no attachments) containing the Design Exception or Design Variance Form, a site specific crash analysis, and other supporting documents into the folder which matches the project oversight Design Exception type or Design Variance. The Design Exception or Design Variance Form should be flattened or printed to Adobe (no longer fillable). However, the Project Manager should also save a copy of the fillable form for future


14.11 (continued)

DESIGN EXCEPTIONS / VARIANCES

revisions. Changing the "state" of the document to "next" will shift control of the DE document to the Design Exception Coordinator for comments or the DV document to the Region Associate Engineer Development. The Project Manager should address the e-mail that appears after changing state, to the appropriate recipient (DE Coordinator for DE or Region Associate Engineer, Development for DV while maintaining the E-ProjectWise address) to indicate that a Design Exception or Variance has been submitted A similar return e-mail indicates that control has shifted back to the Project Manager with comments provided. Revised documents should be inserted into the Adobe file with comment sheets deleted. Electronic signatures are added to the Design Exception or Variance, Crash Analysis, and Crash Analysis Approval Memo (if necessary) only after all changes are made and the documents are ready to be reviewed by the Engineer of Road Design or the Chief Structure Design Engineer (for DE’s) or Region Associate Engineer, Development (for DV’s).

For projects with “MDOT Oversight”, the completed Design Exception Request (Form DE26) must be approved and signed by the Engineer of Road Design or the Chief Structure Design Engineer. For Projects of Division Interest (PoDI), the completed Design Exception Request (Form DE26) must be approved and signed by the Engineer of Road Design or the Chief Structure Design Engineer and subsequently approved by the FHWA Area Engineer. The Design Exception Request (Form DE26) and instructions (Form DE26Instructions) for completing the form are available on the MDOT website.

Design Variances (Form DV26) are signed by the Region Associate Engineer, Development who then changes the state of the DV to complete the DV process.

For additional information see Sections 3.09.02C, 3.10.03, 3.11.02D and 3.11.03B.

14.12 (revised 12-17-2018)

REQUEST FOR SURVEY / MAPPING (PPD Task Descriptions 3310, 3320, 3330, 3340, 3350 & 4510)

Once the scope is verified, the need for a ground survey and/or aerial photography and/or laser scanning for mapping should be determined. Requests for this work can be made by the Region System Manager, Project Manager/Cost and Scheduling Engineer, or the Design Unit Leader. Ideally, the need for, and the requirements of, survey and mapping on a project should be discussed and agreed upon at the Scope Verification Meeting.

If Right-of-Way (ROW) may be acquired for the project, an early control survey should be ordered immediately to enable Real Estate personnel to begin landowner contact and reduce the timeline through the critical path. This early control survey would consist of horizontal survey control being set throughout the project area, government corners being tied in to the coordinate system, and enough property corners being tied to develop approximate non-legal ROW and property lines throughout the project area.

The Survey/Mapping Action Request (Form 0226) should be used to initiate the work. If survey and/or mapping work was ordered and completed during the Call-for-Projects process or under an EPE phase, and additional information is required, a pick-up survey can be ordered using the above forms.

All survey requests should be directed to the Supervising Land Surveyor or Region Surveyor. The Region will decide whether to do the project themselves or request assistance from Lansing survey staff, either in the field or in hiring consultant surveyors. This should be done as soon as possible to allow for the survey and mapping to be completed in a timely manner that does not impact the project’s critical path.

MICHIGAN DESIGN MANUAL BRIDGE DESIGN - CHAPTER 7: LRFD

7.01.04

Design Loading (8-20-2009)

The design loading is as specified in A 3.6.1.2 of AASHTO LRFD with the exception that the design tandem as specified in a.3.6.1.2.3 shall be replaced with a single 60 kip load.

A. Interstate and Trunklines (8-20-2009)

Vehicular live loading on the roadways of bridges designated HL-93 Mod, shall consist of 1.2 times the combination of the:

Design truck or single 60 kip load Design lane load

Where 90% of two design trucks are combined with 90% of the effect of a lane load for both negative moment and pier reactions per A.3.6.1.3 a 1.2 multiplier shall be applied to the resulting moment or load. Each design lane under consideration shall be occupied by either the design truck or single 60 kip load, coincident with the lane load, where applicable. The loads shall be assumed to occupy 10.0 ft. transversely within a design lane.

The design truck and design lane load are specified in AASHTO LRFD A 3.6.1.2.2 and A 3.6.1.2.4.

B. Local Roads and Streets (8-20-2009)

Structures carrying local roads or streets are to be designed according to county or city standards. The minimum design load acceptable for streets or primary county roads is HL-93 Mod loading as specified in this entire section. (8-6-92)

The load modifying factor, η (eta), related to ductility, redundancy, and operational importance, shall be considered for less important roads (AASHTO LRFD A 1.3.2.1).

7.01.04 (continued)

C. Pedestrian and Bicycle (Nonmotorized) Bridges

Pedestrian and bicycle (nonmotorized) bridges shall be designed according to the current AASHTO LRFD Bridge Design Specifications A 3.6.1.6. and current edition of the Guide Specifications for Design of Pedestrian Bridges. The assumed live load is 90 LBS/SFT. Consideration shall also be given to maintenance vehicles with regard to design loadings and horizontal clearances. For Clear Bridge Width, w, greater than 10'-0", use an H10 truck. For w between 7'-0" and 10'-0", use an H5 truck. Where vehicular access is prevented by permanent physical methods (bollards, gates, etc.) or for w less than 7'-0" the bridge does not need to be designed for a maintenance vehicle.] (8-20-2009) (11-28-2011) (5-25-2015)

D. Railroad Bridges

Railroad bridges are designed according to the current AREMA Specifications, with the Cooper loading established by the railroad company.

E. Section combined with 7.01.04 C. (5-25-2015)

F. Deck Replacement, Bridge Widening or Lengthening

When an existing deck is to be replaced or the structure is to be widened or lengthened, the proposed reconstruction should be designed according to LRFD where practicable. In cases where LRFD cannot be used, the design method shall be approved by the MDOT Chief Structure Design Engineer. (8-20-2009) (11-28-2011) (3-26-2018) (5-27-2020)

G. Ice Force on Piers

All piers that are subjected to the dynamic or static force of ice shall be designed according to the current AASHTO LRFD Bridge Design Specifications. (8-20-2009)


7.01.04 (continued)

Design Loading

H. Future Wearing Surface

All new bridges and bridge replacements shall be designed for a future wearing surface load of 25 LBS/SFT. (5-6-99)

I. Stay In Place Forms

For new bridges or superstructure replacements a design load of 15 LBS/SFT should be added for the use of stay in place metal forms. (5-6-99)

J. Barrier Loads

For purposes of beam design, the barrier dead load can be distributed equally to all beams. (AASHTO Std. Specs 17th edition 3.23.2.3.1.1 & AASHTO LRFD 4.6.2.2) However, when calculating superstructure loads on the substructure, particularly for cantilevered pier caps, 75% of the barrier dead load should be applied with the fascia beam load. The remaining 25% of the barrier load should be applied with the first interior girder load. (8-20-2009)

7.01.05

Fatigue Resistance

The nominal fatigue resistance shall be determined using a structure design life of 75 years and the truck ADTT averaged over the design life. A note providing this information should be placed on the General Plan of Structure sheet (see Section 8.05). Design shall be according to AASHTO LRFD Bridge Design Specifications 3.6.1.4 & 6.6.1. (8-20-2009)

7.01.06

Deflection

A. Deflection Limits (8-20-2009)

Deflection limits shall be as specified in the current AASHTO LRFD Bridge Design Specifications A 2.5.2.6.2.

The live load shall be taken from A 3.6.1.3.2.

B. Cantilever Deflection Computation

In computing the live load plus dynamic load allowance deflection of cantilevers of composite anchor span, the gross section of the anchor span is to be used. The length of the composite section for this analysis is to be assumed to extend from the bearing line to the point of dead load contraflexure. (5-27-2020)

7.01.07

Temperature Range

A. The temperature range used to determine thermal forces and movements shall be in conformance with AASHTO "cold climate" temperature range.

B. The type of structure used in determining the temperature range, per AASHTO, shall be defined by the material of the main supporting members of the superstructure or substructure being considered.

MICHIGAN DESIGN MANUAL BRIDGE DESIGN

7.01.04(continued)

Design Loading

J. Barrier Loads

For purposes of beam design, the barrier dead load can be distributed equally to all beams. (AASHTO Std. Specs 17th edition 3.23.2.3.1.1 & AASHTO LRFD 4.6.2.2) However, when calculating superstructure loads on the substructure, particularly for cantilevered pier caps, 75% of the barrier dead load should be applied with the fascia beam load. The remaining 25% of the barrier load should be applied with the first interior beam load. (11-28-2011)

7.01.05

Fatigue Stresses

The allowable stress range should be determined using a structure design life of 75 years and the truck ADT expected at bridge opening. A note providing this information should be placed on the General Plan of Structure sheet (see Section 8.05). (8-6-92)

7.01.06

Deflection

A. Deflection Limits (5-6-99)

LOADING SIMPLE AND CONTINUOUS SPANS

CANTILEVER

HS25 L/800 L/300

HS2044 L/1000 L/375

Pedestrian only L/800 L/300

Timber Bridges L/375 ------

B. Cantilever Deflection Computation

In computing the live load plus impact deflection of cantilevers of composite anchor span, the gross section of the anchor span is to be used. The length of the composite section for this analysis is to be assumed to extend from the bearing line to the point of dead load contraflexure.

7.01.07

Temperature Range

A. The temperature range used to determine thermal forces and movements shall be in conformance with AASHTO "cold climate" temperature range.

B. The type of structure used in determining the temperature range, per AASHTO, shall be defined by the material of the main supporting members of the superstructure or substructure being considered.

7.01.08

Vertical Clearance

A. Requirements

The desired vertical bridge underclearances should be provided as indicated in the following table. If the desired underclearances cannot be provided, then the minimum underclearances shall be met. Where it is considered not feasible to meet these minimums, a design exception shall be requested from the Engineer of Road Design and subsequently to the FHWA (approvals designated in the Project Specific Oversight Agreement (PSOA)) and from MDOT Bureau of Bridges and Structures, Chief Structure Design Engineer on "MDOT Oversight" projects (see Section 12.03 also). See the vertical clearance design exception matrix in Appendix 12.02.01. Requests to further reduce the underclearance of structures with existing vertical clearance less than indicated in the following table should be made only in exceptional cases. (12-5-2005) (1-14-2013) (6-22-2015) (5-27-2020)


7.01.08 (continued)

Vertical Clearance

A. Requirements

VERTICAL CLEARANCE REQUIREMENT TABLE (11-28-2011) (6-22-2015)


All Construction

(Desired)

New Construction

(Min *)

Road 4R Construction

(Min *)

Bridge 4R Construction

(Min *)

3R Construction

(Min *)

Freeways 16'-3" 16'-0" 16'-0" 16'-0" 16'-0" ***

NHS Arterials (Local & Trunkline) 16'-3" 16'-0"

Maintain Existing** and 14'-6" Min 16'-0"

Maintain Existing** and 14'-0" Min

Non NHS Arterials (Local & Trunkline) 16'-3" 14'-6"




Collectors, Local Roads & Special Routes(1) 14'-9" 14'-6"




3R = Rehabilitation, Restoration, Resurfacing 4R = Reconstruction

* Minimum Vertical Clearance must be maintained over complete usable shoulder width.

** Existing vertical clearances greater than or equal to the minimums shown may be retained without a design exception. Vertical clearance reductions that fall below the minimums for new construction require a design exception. (6-22-2015)

*** Existing vertical clearances may be retained (or increased) without a design exception unless a pattern of high load hits exist. Vertical clearance reductions below the standard (table value) require design exceptions. (5-27-2020)

(1) Special Routes are in Highly Urbanized Areas (where little if any undeveloped land exists adjacent to the roadway) where an alternate route of 16'-0" is available or has been designated. Bridges located over Special Routes in Highly Urbanized Areas can be found on the MDOT website at: http://mdotcf.state.mi.us/public/design/files/englishbridgemanual/Exempt_Structures.pdf. (5-28-2013)

Ramps and roadways connecting a Special Route and a 16’-0” route require a vertical clearance minimum of 14’-6” (14'-9" desired). Ramps and roadways connecting two 16’-0” routes require a vertical clearance minimum of 16’-0” (16'-3" desired). (8-20-2009)

Information on the NHS systems can be obtained by contacting the Statewide Planning Section, Bureau of Transportation Planning or found on the MDOT website at: http://www.michigan.gov/mdot-nfc(11-28-2011)

Pedestrian bridges are to provide 1'-0" more underclearance than that required for a vehicular bridge. For Freeways (Interstate and non Interstate), including Special Route Freeways, the desired underclearance shall be 17’-3” (minimum 17'-0"). (11-28-2011)

A vertical underclearance of 23'-0" is required for highway grade separations over railroads when constructing a new bridge or removing the existing superstructure. For preventative maintenance, rehabilitation and deck replacement projects the existing railroad vertical underclearance does not need to be increased unless requested by the Railroad. (11-28-2011)

Clearance signs are to be present for structures with underclearance of 16’-0” or less (show dimensions 2” less than actual). See MDOT Traffic and Safety Sign Design, Placement, and Application Guidelines for additional information and guidelines. (8-20-2009) (11-28-2011) (11-21-2013)(3-25-2019)


7.01.08

Vertical Clearance

A. Requirements

The desired vertical bridge underclearances should be provided as indicated in the following table. If the desired underclearances cannot be provided, then the minimum underclearances shall be met. Where it is considered not feasible to meet these minimums, a design exception shall be requested from the Engineer of Road Design and subsequently to the FHWA (approvals designated in the Project Specific Oversight Agreement (PSOA)) and from MDOT Bureau of Bridges and Structures, Chief Structure Design Engineer on "MDOT Oversight" projects (see Section 12.03 also). See the vertical clearance design exception matrix in Appendix 12.02.01. Requests to further reduce the underclearance of structures with existing vertical clearance less than indicated in the following table should be made only in exceptional cases. (12-5-2005) (1-14-2013) (6-22-2015) (5-27-2020)


7.01.08 (continued)

Vertical Clearance

A. Requirements

VERTICAL CLEARANCE REQUIREMENT TABLE (8-20-2009) (6-22-2015)


All Construction

(Desired)

New Construction

(Min *)

Road 4R Construction

(Min *)

Bridge 4R Construction

(Min *)

3R Construction

(Min *)

Freeways 16'-3" 16'-0" 16'-0" 16'-0" 16'-0" ***

NHS Arterials (Local & Trunkline) 16'-3" 16'-0"

Maintain Existing** and 14'-6" Min 16'-0"


Non NHS Arterials (Local & Trunkline) 16'-3" 14'-6"




Collectors, Local Roads & Special Routes(1) 14'-9" 14'-6"




3R = Rehabilitation, Restoration, Resurfacing 4R = Reconstruction

* Minimum Vertical Clearance must be maintained over complete usable shoulder width.

** Existing vertical clearances greater than or equal to the minimums shown may be retained without a design exception. Vertical clearance reductions that fall below the minimums for new construction require a design exception. (6-22-2015)

*** Existing vertical clearances may be retained (or increased) without a design exception unless a pattern of high load hits exist. Vertical clearance reductions below the standard (table value) require design exceptions. (5-27-2020)

(1) Special Routes are in Highly Urbanized Areas (where little if any undeveloped land exists adjacent to the roadway) where an alternate route of 16'-0" is available or has been designated. Bridges located over Special Routes in Highly Urbanized Areas can be found on the MDOT website at: http://mdotcf.state.mi.us/public/design/files/englishbridgemanual/Exempt_Structures.pdf. (5-28-2013)

Ramps and roadways connecting a Special Route and a 16’-0” route require a vertical clearance minimum of 14’-6” (14'-9" desired). Ramps and roadways connecting two 16’-0” routes require a vertical clearance minimum of 16’-0” (16'-3" desired). (8-20-2009)

Information on the NHS systems can be obtained by contacting the Statewide Planning Section, Bureau of Transportation Planning or found on the MDOT website at: http://www.michigan.gov/mdot-nfc(11-28-2011)

Pedestrian bridges are to provide 1'-0" more underclearance than that required for a vehicular bridge. For Freeways (Interstate and non Interstate), including Special Route Freeways, the desired underclearance shall be 17’-3” (minimum 17'-0"). (8-20-2009)

A vertical underclearance of 23'-0" is required for highway grade separations over railroads when constructing a new bridge or removing the existing superstructure. For preventative maintenance, rehabilitation and deck replacement projects the existing railroad vertical underclearance does not need to be increased unless requested by the Railroad. (11-28-2011)

Clearance signs are to be present for structures with underclearance of 16’-0” or less (show dimensions 2” less than actual). See MDOT Traffic and Safety Sign Design, Placement, and Application Guidelines for additional information and guidelines. (8-20-2009) (11-28-2011) (11-21-2013) (3-25-2019)


7.02.05

Bearings

A. Sole Plates

Plate thicknesses are to be specified in ¼” increments. For beveled sole plates, this ¼” increment is based on the maximum thickness.

For steel beams, sole plates are to be beveled when the calculated bevel is greater than 1% for curved steel bearings and greater than 0.5% for elastomeric bearings. For requirements for prestressed concrete beams, see Subsection 7.02.18. (8-6-92)

B. Elastomeric Pads

Elastomeric pads (⅛”) are required under all steel masonry plates and are to be 1½” longer and wider than the masonry plates. (10-24-2001)

C. Elastomeric Bearings

Plain bearings shall have a shear modulus, G, of 200 (±30psi), laminated bearings shall have a shear modulus of 100 psi (±15psi). Pads shall be 4” minimum (generally 6”) by 34” with ¾” minimum thickness (increase in ¼” increments). (11-28-2011)

Fabric laminated (cotton-duck or other fiber reinforcement) bearings shall not be used unless approved by MDOT Structural Fabrication Engineer or MDOT Chief Structure Design Engineer. (3-20-2017) (3-26-2018) (5-27-2020)

Additional information (polymer type, minimum low-temperature grade, etc.) can be found at MDOT’s Elastomeric Bearing Guidance Document. (3-20-2017)

D. Anchor Bolts

Calculated lengths of bridge anchor bolts should be based on a bolt projection of 1" beyond the nut. (5-6-99)

7.02.06

Precamber - Steel Beams

Where dead load deflection, vertical curve offset, and deflection due to field welding (rare occurrence) is greater than ¼”, the beams shall have a compensating camber. Camber is to be figured to the nearest ¼” and shall be parabolic.

In certain instances, such as for continuous spans or long cantilevers, reverse camber should be called for in order to obtain uniform haunch depths.

When several beams in a bridge have corresponding camber ordinates which differ only slightly from each other, the Engineer should attempt to average these into one set for all beams.

7.02.07

Moment of Inertia - Composite Beam

The composite moment of inertia shall be used throughout positive moment regions. This moment of inertia is to be used in negative moment regions to compute beam stiffness only.

7.02.08

Multiple Span Design

A. Beam Depth

Use the same depth beams for all spans with the longest span controlling the beam depth.

B. Composite Design

Composite design shall be used on all spans. Composite design uses the entire deck/slab thickness versus deck/slab stand-alone design which eliminates the top 1 ½” wearing surface. (5-6-99) (8-17-2015)

C. Suspended Spans

The suspended span should be poured first (see Section 7.02.01).


7.02.05

Bearings (continued)

C. Elastomeric Bearings

Plain bearings shall have a shear modulus, G, of 200 (±30psi), laminated bearings shall have a shear modulus of 100 psi (±15psi). Pads shall be 4” minimum (generally 6”) by 34” with ¾” minimum thickness (increase in ¼” increments). (8-20-2009)

Design steel-reinforced elastomeric bearings with AASHTO LRFD Method A. Method B shall not be used unless approved by MDOT Structural Fabrication Engineer. (11-28-2011) (3-26-2018)

Fabric laminated (cotton-duck or other fiber reinforcement) bearings shall not be used unless approved by MDOT Structural Fabrication Engineer or MDOT Chief Structure Design Engineer. (3-20-2017) (3-26-2018) (5-27-2020)

Additional information (polymer type, minimum low-temperature grade, etc.) can be found at MDOT’s Elastomeric Bearing Guidance Document. (3-20-2017)

D. Anchor Bolts

Calculated lengths of bridge anchor bolts should be based on a bolt projection of 1" beyond the nut. (5-6-99)

7.02.06

Precamber - Steel Beams

Where dead load deflection, vertical curve offset, and deflection due to field welding (rare occurrence) is greater than ¼”, the beams shall have a compensating camber. Camber is to be figured to the nearest ¼” and shall be parabolic.

In certain instances, such as for continuous spans or long cantilevers, reverse camber should be called for in order to obtain uniform haunch depths.

When several beams in a bridge have corresponding camber ordinates which differ only slightly from each other, the Engineer should attempt to average these into one set for all beams.

7.02.07

Moment of Inertia - Composite Beam

The composite moment of inertia shall be used throughout positive moment regions. This moment of inertia is to be used in negative moment regions to compute beam stiffness only.

7.02.08

Multiple Span Design

A. Beam Depth

Use the same depth beams for all spans with the longest span controlling the beam depth.

B. Composite Design

Composite design shall be used on all spans. Composite design uses the entire deck/slab thickness versus deck/slab stand-alone design which eliminates the top 1 ½” wearing surface. (5-6-99) (8-17-2015)

C. Suspended Spans The suspended span should be poured first (see Section 7.02.01).


7.02.12

Welding

All welding details are to be according to AWS specifications, except for minimum fillet weld sizes, which should be as shown in the Standard Specifications. Any intended deviations are to be called to the attention of the MDOT Chief Structure Design Engineer. (5-6-99) (5-27-2020)

Plans should show welding details but should not show the size unless a deviation from AWS specifications is intended.

Plans should also show beam or girder flange tension and stress reversal zones where lifting lugs will not be permitted.

7.02.13

Field Splices in Plate Girders

A. General

Girder Length Field Splice0’ to 125' None provided.

Over 125' to 160'

Field splice is shown on plans as optional; it is designed and detailed, but not paid for.

Over 160' Field splice is designed, detailed, and paid for. *

Fabricators that wish to field splice other than as called for on the plans will need prior Bridge Design Project Manager approval. (5-27-2020)

* Additional steel weight from splices will be added to quantity for “Structural Steel, Plate, Furn and Fab”. (12-22-2011)

7.02.13 (continued)

B. Location

Field splices are to be located at low-stress areas at or near the point of contraflexure for continuous spans.

C. Bolts

All high strength bolts are to be hot-dip galvanized. (3-18-2013)

7.02.14

Diaphragms and Crossframes

A. Orientation

When bridges are on grades, the diaphragm or crossframe connection plates are to be set normal to the flange.

B. End Diaphragms

End diaphragms or crossframes are required at ends of beams to support the end of slab unless it is supported by other means. Curved girders shall have diaphragms or crossframes placed at the centerline of support. To provide access for painting, these diaphragms or crossframes shall be no closer than 2'-0" from the beam end at independent backwalls and shall have no less than 2'-0" of clearance at simple supports. (5-6-99)


7.02.12

Welding

All welding details are to be according to AWS specifications, except for minimum fillet weld sizes, which should be as shown in the Standard Specifications. Any intended deviations are to be called to the attention of the MDOT Chief Structure Design Engineer. (5-6-99) (5-27-20)

Plans should show welding details but should not show the size unless a deviation from AWS specifications is intended.

Plans should also show beam or girder flange tension and stress reversal zones where lifting lugs will not be permitted.

7.02.13

Field Splices in Plate Girders

A. General

Girder Length Field Splice

0’ to 125' None provided.

Over 125' to 160'

Field splice is shown on plans as optional; it is designed and detailed, but not paid for.

Over 160' Field splice is designed, detailed, and paid for. *

Fabricators that wish to field splice other than as called for on the plans will need prior Bridge Design Project Manager approval. (5-27-2020)

* Additional steel weight from splices will be added to quantity for “Structural Steel, Plate, Furn and Fab”. (12-22-2011)

7.02.13 (continued)

B. Location

Field splices are to be located at low-stress areas at or near the point of contraflexure for continuous spans.

C. Bolts

All high strength bolts are to be hot-dip galvanized. (3-18-2013)

7.02.14

Diaphragms and Crossframes

A. Orientation (8-20-2009)

Diaphragms or cross-frames shall be provided at abutments, piers and hinge joints. Intermediate diaphragms may be used between beams in curved systems or where necessary to provide torsional resistance and support the deck at points of discontinuity or at angle in girders.

The need for diaphragms or cross-frames shall be investigated for all stages of assumed construction procedures and the final condition. Diaphragms or cross-frames required for conditions other than the final condition may be specified to be temporary bracing.

B. End Diaphragms

End diaphragms or crossframes are required at ends of beams to support the end of slab unless it is supported by other means. Curved girders shall have diaphragms or crossframes placed at the centerline of support. To provide access for painting, these diaphragms or crossframes shall be no closer than 2'-0" from the beam end at independent backwalls and shall have no less than 2'-0" of clearance at simple supports. (5-6-99)


8.05

GENERAL PLAN OF STRUCTURE SHEET

A1. The design of this structure is based on 1.2 times the current AASHTO LRFD Bridge Design Specification HL-93 loading with the exception that the design tandem portion of the HL-93 load definition shall be replaced by a single 60 kip axle load before application of this 1.2 factor. The resulting load is designated HL-93 Mod. Live load plus dynamic load allowance deflection does not exceed (1/425*) (1/800) (1/1000**) of span length (and 1/375) (1/300) of cantilever arm. [*Wood construction.] [**Use for structures with pedestrian loads.] [See Subsection 7.01.06 for deflection limits.] (8-20-2009)

A2. The design of this structure is based on current AASHTO LRFD Bridge Design Specification pedestrian loading of 90 psf (and a maintenance vehicle (H5) (H10) loading, not acting concurrently). Live load deflection does not exceed 1/360 of span length and 1/220 of cantilever arm. [Use for pedestrian bridges. For Clear Bridge Width, w, greater than 10'0", use an H10 truck. For w between 7'-0" and 10'-0", use an H5 truck. For w less than 7'-0" the bridge does not need to be designed for a maintenance vehicle.]

(11-28-2011) (5-25-2015)

A3. The design of the deck slab is based upon the strip method as defined in the current AASHTO LRFD Bridge Design Specification, utilizing HL-93 Loading.

(8-20-2009) (5-27-2020)

8.05 (continued)

B1. The (reconstruction) (rehabilitation) design is based on 1.2 times the current AASHTO LRFD Bridge Design Specification HL93 loading with the exception that the design tandem portion of the HL-93 load definition shall be replaced by a single 60 kip axle load before application of this 1.2 factor. The resulting load is designated HL-93 Mod. Live load plus dynamic load allowance deflection does not exceed (1/425**) (1/800) (1/1000***) of span length (and 1/375) (1/300) of cantilever arm. The original structure was designed for (and alternate military*) loading (based on AASHTO Standard Specifications for Highway Bridges). [*Used only for structures on interstate routes.] [**Wood construction.] [***Use for structures with pedestrian loads.] [See Subsection 7.01.06 for deflection limits.] [Use note for LRFD method of design.] (8-20-2009)

B2. The (reconstruction) (rehabilitation) design is based on the 17th Edition of AASHTO Standard Specifications for Highway Bridges (HS25) (HS20-44) (and alternate military*) loading. Live load plus impact deflection does not exceed (1/425) (1/800) (1/1000) of span length (and 1/375) (1/300) of cantilever arm. The original structure was designed for (and alternate military*) loading based on AASHTO Standard Specifications for Highway Bridges. [*Use only for structures on interstate routes.] [See 17th

Edition of AASHTO for deflection limits.] [Use note for Load Factor method of design.] (8-20-2009)


12.02

GEOMETRIC CRITERIA

(9-1-88) While it is desirable to improve all structures to current design standards, upgrading to this extent may not be considered cost effective where a project is otherwise programmed for only rehabilitation. Criteria for roadway widths and design loading structural capacity have been established in A Policy on Design Standards - Interstate System, 2005, and A Policy on Geometric Design of Highways and Streets, 2011, 6th

Edition, published by AASHTO. These criteria are based on the type of roadway carried by the structure and are summarized in Appendix 12.02. Criteria for structures carrying interstate freeways are provided in AASHTO’s 2005 edition of A Policy On Design Standards - Interstate System. The policy states: “The standards used for horizontal alignment, vertical alignment, and widths of median, traveled way, and shoulders for resurfacing, restoration and rehabilitation projects may be the AASHTO interstate standards that were in effect at the time of the original construction or inclusion into the interstate system.” Non Interstate structures shall adhere to A Policy on Geometric Design of Highways and Streets, 2011, 6th

Edition design criteria (standards). Therefore, if a bridge on a road project is not altered it is subject to design exceptions or design variances for full new/reconstruction standards. (8-20-2009) (3-21-2016) (2-21-2017)

12.02.01

Vertical Clearance (5-1-2000) (5-27-2020)

For Design Exception Requirements for Vertical Clearance see Appendix 12.02.01.

For 3R freeway projects, if the existing vertical clearance is not reduced and a crash pattern involving high load hits does not exist, the vertical clearance may be retained without a design exception. However, if the vertical clearance is reduced to a value less than the standard (table value in Section 7.01.08), a design exception will be required. The format for the design exception does not require a detailed evaluation but should include the basis for the request and review of the accident history and high load hits for the structures in the immediate vicinity of the structure.

For the remaining 3R route classifications (Section 7.01.08), existing vertical clearances greater than or equal to the minimums shown may be retained without a design exception. Vertical clearance reductions that fall below the minimums for new construction require a design exception.


12.07.09

A588 Steel Beams (9-2-2003)

The following rehabilitation situations exist for A588 beams:

1. Little or no section loss (< 20%), painting is not required.

2. Significant section loss (> 20%), the entire structure is painted. This includes projects with beam end repairs.

3. Pin and hanger projects where beams are otherwise in good condition (< 20% section loss), beams are zone painted (with the outside of the fascia beams top coated brown in the zone area).

12.07.10

Partial Painting

Where structural steel cleaning and coating involves only partial sections of beams or diaphragms the entire perimeter of the beams or diaphragms, less any portions encased in concrete, shall be cleaned and coated. Cleaning and Coating shall be according to the Standard Specifications for Construction or Special Provisions. (3-26-2012)

12.08

MISCELLANEOUS REHABILITATION

Some miscellaneous rehabilitation is significant and is programmed for the specific purpose. More frequently, miscellaneous work is an adjunct to other work. As such, its nature and cost should be determined as early as possible so that the primary project programming can be adjusted.

Include saw cut depth dimensions when removing portions of abutments, piers and columns on the plans. (8-20-2009)

12.08.01

Field Inspections

The Plan Review Meeting with a field inspection should be conducted on all rehabilitation projects. This inspection should be made within six months of the contract letting to most accurately determine the extent of deterioration. If a project is postponed, it may be necessary to conduct a second inspection. (5-27-20)

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