New York State Department of Transportation

ENGINEERINGBULLETIN

EB13-030

Expires one year after issue unless replaced sooner

Title: HIGHWAY DESIGN MANUAL REVISION N0. 73 - CHAPTER 2 - DESIGN CRITERIA Target Audience:

Manufacturers (18) Local Govt. (31) Agencies (32)

Surveyors (33) Consultants (34) Contractors (39) ____________( )

Approved: /s/Stephen A. Zargham___________ Stephen A. Zargham, PE Director, Design Quality Assurance Bureau

9/03/13

Date

ADMINISTRATIVE INFORMATION: • This Engineering Bulletin (EB) is effective beginning with projects submitted for design

approval on or after January 1, 2014, but designers may begin implementation before the effective date.

• Superseded Issuances: None • Disposition of Issued Materials: These changes will be incorporated into the Highway Design

Manual, Chapter 2 by this revision. PURPOSE: The purpose of this EB is to announce the availability of Revision 73 to the Highway Design Manual (HDM) – Chapter 2 – Design Criteria. TECHNICAL INFORMATION:

• HDM Exhibit 2-9 Traveled Way Widths for Ramps and Turning Roadways is revised to: 1) Simplify the traveled way width determination by providing one table for interstate

ramps and another table for non-interstate ramps and turning roadways, including non-interstate highways that are designated as Qualifying Highways (see HDM section 2.5.3.2). This results in minimum and economical traveled way widths while meeting AASHTO recommendations for large vehicle accommodation. Since Exhibit 2-9a directly addresses the requirements for the interstate tractor trailer (WB-67/WB-20), Condition D is no longer needed.

2) Update the values and instructions to reflect guidance in the 2011 AASHTO Green Book;

3) Correct errors in the traveled way width values in the previous version of HDM Exhibit 2-9.

• Highway Design Manual (HDM) Section 2.7.5.2B Lane Width is revised to read: “B. Traveled Way Width Determine minimum traveled way width from Exhibits 2-9a or 2-9b, as appropriate. Use Exhibit 2-9a for interstate ramps and Exhibit 2-9b for non-interstate ramps and turning roadways, including non-interstate highways that are designated as Qualifying Highways.”

EB 13-030 Page 2 of 2

• Typographical errors on 2 additional pages have been corrected. On page 2-37 Note 7 has been corrected to read “For bridges, determine the lane and shoulder width from the NYSDOT Bridge Manual, Section 2.” On page 2-49 the last 2 bullets next to the text have been removed. The text remains.

• A correction was made on page 2-27. The following language was added under Grade in Section 2.7.2.1 E to correct a previous omission: “Determine maximum from Exhibit 2-3”.

TRANSMITTED MATERIALS:

• Revised Exhibits 2-9a and 2-9b and a metric version (Exhibits M2-9a and M2-9b) are available at: https://www.dot.ny.gov/divisions/engineering/design/dqab/hdm/chapter-2 Revision to HDM Section 2.7.5.2B Lane Width is also available at the above link.

• The pages modified by this revision can be found in the HDM Revisions Log at:

https://www.dot.ny.gov/divisions/engineering/design/dqab/hdm/hdm-revised-logs CONTACT: Direct questions regarding this issuance to Mary Ricard, PE (Mary.Ricard@dot.ny.gov) of the Design Quality Assurance Bureau.

HIGHWAY DESIGN MANUAL

Chapter 2 Design Criteria

Revision 73 (Limited Revision)

September 3, 2013

9/3/2013

Section Changes 2.7.2.1 Language was added under Grade in item E to correct a previous omission:

“Determine maximum from Exhibit 2-3”. Exhibit 2-5 Typographical error corrected in Note 7 to read “For bridges, determine the lane

and shoulder width from the NYSDOT Bridge Manual, Section 2.” 2.7.5.2A Removed the last 2 bullets next to the text. The text remains. 2.7.5.2B Revised to properly refer to revised Exhibits 2-9a and 2-9b. Exhibit 2-9 Changed to simplify the traveled way width determination by providing one table for

interstate ramps and another table for non-interstate ramps and turning roadways, including non-interstate highways that are designated as Qualifying Highways.

Eliminates the need for traffic condition D. Exhibit 2-9 Updates the values and instructions to reflect guidance in the 2011 AASHTO Green

Book. Exhibit 2-9 Corrected errors in the traveled way width values.

9/3/2013

2.9 REFERENCES ............................................................................................................. 2-65 APPENDIX A- METRIC VALUES FOR STANDARDS ............................................................. 2-66

M2.7.1 Interstates and Other Freeways ........................................................................... 2-66 M2.7.2 Arterials ................................................................................................................ 2-71 M2.7.3 Collector Roads and Streets ................................................................................ 2-79 M2.7.4 Local Roads and Streets ...................................................................................... 2-86 M2.7.5 Other Roadways ................................................................................................... 2-93

LIST OF EXHIBITS

Exhibit Title Page 2-1 Functional Classification of Highways - Various Sources ........................................... 2-7 2-1a Horizontal Clearance ................................................................................................ 2-18 2-2 Design Criteria for Interstates and Other Freeways ................................................. 2-26 2-3 Design Criteria for Rural Arterials.............................................................................. 2-29 2-4 Design Criteria for Urban Arterials ............................................................................ 2-33 2-5 Design Criteria for Rural Collectors ........................................................................... 2-37 2-6 Design Criteria for Urban Collectors.......................................................................... 2-41 2-7 Design Criteria for Local Rural Roads ....................................................................... 2-44 2-8 Design Criteria for Local Urban Streets..................................................................... 2-48 2-9a Traveled Way Widths for Interstate Ramps ............................................................. 2-53a 2-9b Traveled Way Widths for Non-Interstate Ramps and Turning Roadways ............... 2-53b 2-10 Design Criteria for Turning Roadways ...................................................................... 2-54 2-11 Minimum Radii and Superelevation for Low-Speed Urban Streets ........................... 2-57 2-12 Minimum Radii for Design Superelevation Rates, Design Speeds, and emax = 4% ... 2-58 2-13 Minimum Radii for Design Superelevation Rates, Design Speeds, and emax = 6% ... 2-59 2-14 Minimum Radii for Design Superelevation Rates, Design Speeds, and emax = 8% ... 2-60 2-15 Nonstandard Feature Justification Form ................................................................... 2-63 2-16 Design Criteria Table ................................................................................................ 2-64 M2-2 Design Criteria for Interstates and Other Freeways ................................................. 2-70 M2-3 Design Criteria for Rural Arterials.............................................................................. 2-74 M2-4 Design Criteria for Urban Arterials ............................................................................ 2-78 M2-5 Design Criteria for Rural Collectors ........................................................................... 2-81 M2-6 Design Criteria for Urban Collectors.......................................................................... 2-85 M2-7 Design Criteria for Local Rural Roads ....................................................................... 2-88 M2-8 Design Criteria for Local Urban Streets..................................................................... 2-92 M2-9a Traveled Way Widths for Interstate Ramps ............................................................. 2-97a M2-9b Traveled Way Widths for Non-Interstate Ramps and Turning Roadways ............... 2-97b M2-10 Design Criteria for Turning Roadways ...................................................................... 2-98 M2-11 Minimum Radii and Superelevation for Low-Speed Urban Streets ......................... 2-101 M2-12 Minimum Radii for Design Superelevation Rates, Design Speeds, and emax = 4% . 2-102 M2-13 Minimum Radii for Design Superelevation Rates, Design Speeds, and emax = 6% . 2-103 M2-14 Minimum Radii for Design Superelevation Rates, Design Speeds, and emax = 8% . 2-104

DESIGN CRITERIA 2-27

9/3/2013 §2.7.2.1

2.7.2 Arterials

2.7.2.1 Rural Arterials The design criteria for undivided and divided rural arterials are:

A. Design Speed

The design speed is either: maximum functional class speed or a speed based on the anticipated (post-construction) off-peak 85th percentile speed within the range of functional class speeds as shown below. Refer to Section 2.6.1 for guidance on design speed and Chapter 5 of this manual, Section 5.2.4 for methods to determine the off-peak 85th percentile speed. The following are the range of design speeds.

Terrain Minimum Design Speed Maximum Design Speed

Level 40 mph 60 mph

Rolling 40 mph 60 mph

Mountainous 40 mph 50 mph

B. Lane Width

Determine from Exhibit 2-3.

C. Shoulder Width

Determine from Exhibit 2-3.

D. Bridge Roadway Width

Determine from NYSDOT Bridge Manual, Section 2. Note that the bridge roadway width includes the lane and shoulders and is often based on the approach lane and shoulder width determined from Sections B and C, above.

E. Grade

Determine maximum from Exhibit 2-3.

F. Horizontal Curvature

Determine minimum radius from Exhibit 2-3. For curves flatter than the minimum radius, the radius and superelevation on each horizontal curve shall be correlated with the design speed in accordance with the appropriate emax table (Exhibit 2-13 for e max. = 6% or Exhibit 2-14 for emax. = 8%).

G. Superelevation

8% maximum. A 6% maximum may be used in suburban areas to minimize the effect of negative side friction during peak periods with low travel speeds.

DESIGN CRITERIA 2-37

9/3/2013 §2.7.3.1

Exhibit 2-5 Design Criteria for Rural Collectors

Design Speed (mph)

Travel Lane Width (ft.) 1,7 Based on Design Year ADT Turn Lane (ft.) Maximum Percent Grade 2

Min.

Stopping Sight

Distance (ft.)

Min.

Radius Curve (ft.)

emax = 6%

Min.

Radius Curve (ft.)

emax = 8%

ADT Under 400

ADT 400- 1500

ADT

1500- 2000 3

ADT Over

2000 3

Minimum

Desirable

Terrain Level Rolling Mountainous

20 10 4 10 11 12

10

Match Travel Lane Width

7 10 12 115 81 76

25 10 4 10 11 12 7 10 11 155 144 134

30 10 4 10 11 12 7 9 10 200 231 214

35 10 4 10 11 12 7 9 10 250 340 314

40 10 4 11 11 12 7 8 10 305 485 444

45 10 4 11 11 12 7 8 10 360 643 587

50 10 4 11 11 12 6 7 9 425 833 758

55 11 11 12 12 6 7 9 495 1060 960

60 11 11 12 12 5 6 8 570 1330 1200

Shoulder Width (ft.) 7

Notes: 1. Routes designated as Qualifying Highways on the national network of Designated

Truck Access Highways require 12 ft. travel lanes. 2. Short lengths of grade in rural areas, such as grades less than 490 ft. in length, one—way downgrades,

and grades on low-volume (<1500 vpd) rural collectors may be up to 2% steeper than the grades shown above.

3. 11 ft. lanes may be retained where accident rates are acceptable. 4. 9 ft. lanes may be used for design volumes under 250 vpd. 5. .Minimum width is 4 ft. if roadside barrier is used. 4 ft. shoulder is desirable if the shoulder is intended for

occasional pedestrian and/or bicycle use. 6. Shoulder width may be reduced to 4 ft. for design speeds of 40 mph to 60 mph. 7. For bridges, determine the lane and shoulder width from the NYSDOT Bridge Manual, Section 2.

All Speeds

2 5

5 6

6

8

2-49 DESIGN CRITERIA

9/3/2013 §2.7.5.2

2.7.5 Other Roadways

2.7.5.1 Parkways Parkways that are multilane, divided freeways, or expressways with occasional at-grade intersections should follow the standards in Section 2.7.1.2 Other Freeways. Parkways that are two-lane highways or multilane, divided highways with signalized intersections should follow the standards of the design classification established for the subject parkway.

2.7.5.2 Ramps (Turning Roadways for Grade-Separated Highways) Ramps are turning roadways to accommodate high volumes of turning movements between grade-separated highways. Ramps are functionally classified based on the higher-type highway they service. For example, all the ramps to and from an interstate are considered part of the Interstate System. The design criteria for ramps are:

A. Design Speed

A ramp speed study is not required to determine the ramp design speed. The ramp design speed for the design criteria applies to the sharpest ramp curve, usually on the ramp proper. The ramp design speed does not apply to the ramp terminals, which should include transition curves and speed change lanes based on the design speeds of the highways and ramps involved. Desirably, ramp design speed should approximate the off-peak running speeds (50th percentile speeds) on the higher speed intersecting highway, but not exceed 50 mph. Ramps with design speeds over 50 mph should be designed using Section 2.7.1 of this chapter. The minimum design speeds based on ramp type (as illustrated in Exhibit 10-55 of AASHTO’s A Policy on Geometric Design of Highways and Streets, 2004) are:

Loop ramps – 25 mph minimum for highways with design speeds of more than 50 mph. Semidirect connection ramps – 30 mph minimum. Direct connection ramps – 40 mph minimum; 50 mph preferred. Diagonals, outer connections, and one-quadrant ramps - Below is the minimum ramp

design speed related to the highway design speed. The highway design speed is the higher design speed of the interchanging roadways. Highway Design Speed (mph) 40 45 50 55 60 70 75 Min. Ramp Design Speed (mph) 20 25 25 30 30 40 45

2-53a DESIGN CRITERIA

9/3/2013 §2.7.5.2

Exhibit 2-9a Traveled Way Widths for Interstate Ramps(1) Radius on

Inside Edge of Traveled

Way, R (ft)

Traveled Way Width (ft)(2) One-Lane, One-Way

Operation Two-Lane Operation(3) – One-Way or Two-Way

50 See note 4 See note 4 75 See note 4 See note 4 100 See note 4 See note 4 150 23 (17)(5) 32 200 21 (16)(5) 30 300 19 (15)(5) 29 400 18 (15)(5) 28 500 17 (15)(5) 28

Tangent (≥1000 ft) 15 26

Width Modification for Edge Conditions No Stabilized

Shoulder None None

Sloping Curb None None Vertical Curb

One Side Two Sides

Add 1 ft Add 2 ft

Add 1 ft Add 2 ft

Paved Shoulder, one or both sides

Traveled way width for tangent (R≥1000 ft) may be reduced to 12 ft where the

combined left and right shoulder width is 4 ft or

wider.

Deduct 2 ft where the combined left and right shoulder width is 4 ft or

wider

1 For non-interstate ramps and turning roadways use Exhibit 2-9b. 2 The ramp traveled way width may vary according to the radius encountered. In general, the least width is selected, with the width increased in curved segments of the ramp. Taper between different widths in accord with HDM Chapter 5. 3These widths (from AASHTO Green Book 2011 Table 3-29) reflect a combination of separate design vehicles, and will only accommodate two WB-40 design vehicles passing one another. For the rare cases where the design must accommodate WB-67 design vehicles passing one another, use AASHTO Green Book 2011 Table 3-28b to determine the required width. 4 These radii are associated with design speeds lower than the minimum required for interstate ramps in New York State. Retaining these radii on existing interstate ramps requires Non-Standard Feature Justification(s) with a safety and operational analysis of the impact on larger vehicles. New or reconstructed ramps should not use less than a 150 ft radius. 5 The reduced traveled way width included in parenthesis may be used instead if BOTH of the following apply:

a) Right and left shoulders are full depth (required for new or reconstructed ramps only) and widths meet or exceed the minimum shoulder widths from Exhibit 2-10.

b) The cross slope of traveled way and shoulders is on a single plane, as shown in HDM Figure 3-5, 3rd section from top, with no rollover.

DESIGN CRITERIA 2-53b

§2.7.5.2 9/3/2013

Exhibit 2-9b Traveled Way Widths for Non-Interstate Ramps and Turning Roadways(1)

Radius on Inner Edge of Traveled Way, R (ft)

Traveled Way Width (ft)(2)

Case I One-Lane, One-Way

Operation – no provision for passing a stalled

vehicle

Case II One-Lane, One-Way

Operation – with provision for passing a

stalled vehicle

Case III Two-Lane Operation – One-Way or Two-Way

Design Traffic Condition (see definitions below) A B C A B C A B C

50 18 18 23 20 26 30 31 36 45 75 16 17 20 19 23 27 29 33 38 100 15 16 18 18 22 25 28 31 35 150 14 15 17 18 21 23 26 29 32 200 13 15 16 17 20 22 26 28 30 300 13 15 15 17 20 22 25 28 29 400 13 15 15 17 19 21 25 27 28 500 12 15 15 17 19 21 25 27 28

Tangent (≥1000 ft) 12 14 14 17 18 20 24 26 26

Width Modification for Edge Conditions No Stabilized

Shoulder None None None

Sloping Curb None None None Vertical Curb

One Side Two Sides

Add 1 ft Add 2 ft

None

Add 1 ft

Add 1 ft Add 2 ft

Paved Shoulder, one or both sides

Traveled way width for tangent (R≥1000 ft) may be reduced to 12 ft where the

combined left and right shoulder width is 4 ft or

wider.

Deduct the combined left and right shoulder width,

but the traveled way width cannot be less than that required under Case I.3

Deduct 2 ft where the combined left and right shoulder width is 4 ft or

wider.

Design Traffic Condition Definitions A = Predominantly P vehicles, but some consideration for SU trucks B = Single-Unit (SU) Truck and Semitrailer vehicles comprise 5-10% of traffic volume C = Bus and Semitrailer vehicles comprise over 10% of traffic volume 1 For non-interstate highways designated as Qualifying Highways (see section 2.5.3.2), use Design Traffic Condition C and ensure that the design permits a WB-67 design vehicle to negotiate the non-interstate ramp/turning roadway using the full width of the roadway (traveled way plus shoulders).

2 Values are from AASHTO Green Book 2011 Table 3-29. The traveled way width may vary according to the radius encountered. In general, the least width is selected, with the width increased in curved segments. Taper between different widths in accord with HDM Chapter 5. 3 For example, for R=150 ft, Case II, Condition B and combined left and right shoulder width of 9 ft, the traveled way width required is 21-9=12 ft. However, it cannot be less than that required under Case I so 15 ft is required.

2-94 DESIGN CRITERIA

'M2.7.5.2 9/3/2013

B. Traveled Way Width

Determine minimum traveled way width from Exhibits M2-9a or M2-9b, as appropriate. Use Exhibit M2-9a for interstate ramps and Exhibit M2-9b for non-interstate ramps and turning roadways, including non-interstate highways that are designated as Qualifying Highways.

C. Shoulder Width

Determine minimum shoulder widths from Exhibit M2-10.

D. Bridge Roadway Width

The lane and shoulder widths are to be carried across all ramp structures.

E. Grade

Determine maximum from Exhibit M2-10.

F. Horizontal Curvature

Determine minimum radius from Exhibit M2-10. For curves flatter than the minimum radius, the radius and superelevation on each horizontal curve shall be correlated with the design speed in accordance with the appropriate e max table (Exhibit M2-13 for e max. = 6% or Exhibit M2-14 for e max. = 8%).

G. Superelevation

8% maximum. A 6% maximum may be used in urban and suburban areas to minimize the effect of negative side friction during peak periods with low travel speeds.

H. Stopping Sight Distance (Horizontal and Vertical)

Determine minimum and desirable stopping sight distance from Exhibit M2-10.

I. Horizontal Clearance

Right side = greater of shoulder width or 1.8 m and left side = 1.0 m minimum. Where ramps pass under structures, there should be an additional 1.2 m clearance beyond the outside of shoulders to bridge piers or abutments.

DESIGN CRITERIA

9/3/2013 'M2.7.5.2

2-97a

Exhibit M2-9a Traveled Way Widths for Interstate Ramps(1) Radius on Inner Edge of Traveled Way, R (m)

Traveled Way Width (m)(2)

One-Lane, One-Way Operation

Two-Lane Operation(3) – One-Way or Two-Way

15 See note 4 See note 4 25 See note 4 See note 4 30 See note 4 See note 4 50 6.7 (5.0)(5) 9.5 75 5.9 (4.8)(5) 8.9 100 5.5 (4.8)(5) 8.7 125 5.3 (4.8)(5) 8.5 150 5.2 (4.5)(5) 8.4

Tangent (≥300 m) 4.5 7.9

Width Modification for Edge Conditions No Stabilized

Shoulder None None

Sloping Curb None None Vertical Curb

One Side Two Sides

Add 0.3 m Add 0.6 m

Add 0.3 m Add 0.6 m

Paved Shoulder, one or both sides

Traveled way width for tangent (R≥300 m) may be reduced to 3.6 m where the

combined left and right shoulder width is 1.2 m or

wider.

Deduct 0.6 m where the combined left and right

shoulder width is 1.2 m or wider

1 For non-interstate ramps and turning roadways use Exhibit 2-9b. 2 The ramp traveled way width may vary according to the radius encountered. In general, the least width is selected, with the width increased in curved segments of the ramp. Taper between different widths in accord with HDM Chapter 5. 3 These widths (from AASHTO Green Book 2011 Table 3-29) reflect a combination of separate design vehicles, and will only accommodate two WB-12 design vehicles passing one another. For the rare cases where the design must accommodate WB-20 design vehicles passing one another, use AASHTO Green Book 2011 Table 3-28a to determine the required width. 4 These radii are associated with design speeds lower than the minimum required for interstate ramps in New York State. Retaining these radii or proposing them for new/reconstructed ramps requires Non-Standard Feature Justification(s) with a safety and operational analysis of the impact on larger vehicles. New or reconstructed ramps should not use less than a 50 m radius. 5 The reduced traveled way width included in parenthesis may be used instead if BOTH of the following apply:

a) Right and left shoulders are full depth (required for new or reconstructed ramps only) and widths meet or exceed the minimum shoulder widths from Exhibit 2-10.

b) The cross slope of traveled way and shoulders is on a single plane, as shown in HDM Figure 3-5, 3rd section from top, with no rollover.

2-97b

'M2.7.5.2 9/3/2013

Exhibit M2-9b Traveled Way Widths for Non-Interstate Ramps and Turning Roadways(1)

Radius on Inner Edge of Traveled Way, R (m)

Traveled Way Width (m)(2)

Case I One-Lane, One-Way

Operation – no provision for passing a stalled

vehicle

Case II One-Lane, One-Way

Operation – with provision for passing a

stalled vehicle

Case III Two-Lane Operation – One-Way or Two-Way

Design Traffic Condition (see definitions below) A B C A B C A B C

15 5.4 5.5 7.0 6.0 7.8 9.2 9.4 11.0 13.6 25 4.8 5.0 5.8 5.6 6.9 7.9 8.6 9.7 11.1 30 4.5 4.9 5.5 5.5 6.7 7.6 8.4 9.4 10.6 50 4.2 4.6 5.0 5.3 6.3 7.0 7.9 8.8 9.5 75 3.9 4.5 4.8 5.2 6.1 6.7 7.7 8.5 8.9 100 3.9 4.5 4.8 5.2 5.9 6.5 7.6 8.3 8.7 125 3.9 4.5 4.8 5.1 5.9 6.4 7.6 8.2 8.5 150 3.6 4.5 4.5 5.1 5.8 6.4 7.5 8.2 8.4

Tangent (≥300 m) 3.6 4.2 4.2 5.0 5.5 6.1 7.3 7.9 7.9

Width Modification for Edge Conditions No Stabilized

Shoulder None None None

Sloping Curb None None None Vertical Curb

One Side Two Sides

Add 0.3 m Add 0.6 m

None

Add 0.3 m

Add 0.3 m Add 0.6 m

Paved Shoulder, one or both sides

Traveled way width for tangent (R≥300 m) may be reduced to 3.6 m where the

combined left and right shoulder width is 1.2 m or

wider.

Deduct the combined left and right shoulder width,

but the traveled way width cannot be less than that required under Case I.3

Deduct 0.6 m where the combined left and right

shoulder width is 1.2 m or wider.

Design Traffic Condition Definitions A = Predominantly P vehicles, but some consideration for SU trucks B = Single-Unit (SU) Truck and Semitrailer vehicles comprise 5-10% of traffic volume C = Bus and Semitrailer vehicles comprise over 10% of traffic volume 1 For non-interstate highways designated as Qualifying Highways (see section 2.5.3.2), use Design Traffic Condition C and ensure that the design permits a WB-20 design vehicle to negotiate the non-interstate ramp/turning roadway using the full width of the roadway (traveled way plus shoulders).

2 Values are from AASHTO Green Book 2011 Table 3-29. 3 For example, for R=50 m, Case II, Condition B and combined left and right shoulder width of 3 m, the width required is 6.3 – 3 =3.3 m. However, it cannot be less than that required under Case I so 4.6 m is required.