CHARACTERIZING BRIDGE FUNCTIONAL OBSOLESCENCE USING ...docs.trb.org/prp/15-1947.pdf · 1...

Bechtel et al. TRB #15-1947

1

CHARACTERIZING BRIDGE FUNCTIONAL OBSOLESCENCE USING 1

CONGESTION PERFORMANCE MEASURES DETERMINED FROM 2

ANONYMOUS PROBE VEHICLE DATA 3

by 4

Andrew J. Bechtel* 5 The College Of New Jersey 6

2000 Pennington Road 7 Ewing, NJ 08628 8 (609) – 771 -2475 9 [email protected] 10

Thomas M. Brennan Jr. 11 The College of New Jersey 12

[email protected] 13

Jhenifer Mesquita de Araujo 14 The College of New Jersey 15

[email protected] 16

*Corresponding author. Email: [email protected] 17

Word Count: 4,363 words + 11 * 250 words/(figure-table) = 7113 words 18

November 4, 2014 19 20


2

ABSTRACT 1

In the last few years, anonymous probe vehicle data has become a reliable means to 2

evaluate travel time reliability, as well as congestion conditions along highways and major 3

arterials. The data is collected using telematics from commercial and private cellular phones, 4

GPS devices, and on-board vehicle computers. The probe vehicle data is commercially available 5

in one-minute increments along spatially defined roadway segments of varying lengths. This data 6

is being incorporated into local and statewide reports to measure congestion conditions of 7

highway and arterial systems. This paper uses crowd sourced anonymous probe vehicle data to 8

evaluate congestion duration at functionally obsolete bridge structures. The bridges selected were 9

functionally obsolete due to poor ratings in their deck geometry. as defined by National Bridge 10

Inventory (NBI) rating system. These deficiencies are based on a bridge’s traffic capacity as a 11

function of its geometry and the Average Daily Traffic (ADT). These conditions are directly 12

expected to impact the speed and volume of traffic crossing over the bridge causing congestion. 13

An evaluation of the travel times at bridge locations was conducted to determine if a measurable 14

amount of congestion could be observed using probe vehicle data. 15

The methodologies presented in this paper were applied to 37 bridge structures in 16

Burlington County, New Jersey. Approximately 35 million speed data records were analyzed for 17

the 37 bridges to measure congestion. The congestion performance measures were compared to 18

the NBI rating to determine if congestion existed at the bridges as predicted by the NBI system. 19

The comparison showed that a poor rating in deck geometry from the NBI system was not a 20

strong indicator of congestion. The congestion evaluation methodologies presented in this paper 21

where then combined with existing NBI structural ratings to demonstrate alternative bridge 22

management strategies. 23


3

INTRODUCTION 1

The American Society of Civil Engineers (ASCE) 2013 Report Card for America’s Infrastructure 2

gave the country’s bridges an overall grade of C+. The Federal Highway Administration (FHWA) 3

estimates that $20.5 billion dollars needs to be invested annually to correct all of the deficient bridges in 4

the US by the year 2028. This is an annual increase of $8 billion dollars. The ASCE cites one way to 5

mitigate these deficient bridges is to improve asset management methodologies. Currently, 24.9% 6

(151,238) of the country’s bridges are characterized as deficient (1). These deficient bridges are 7

characterized as structurally deficient or functionally obsolete, but can be both in some cases. A 8

structurally deficient bridge requires significant maintenance, rehabilitation, or replacement. These 9

bridges must be inspected at least every year since critical load-carrying elements were found to be in 10

poor condition due to deterioration or damage. (1). Conversely, a functionally obsolete bridge no longer 11

meets the current standards that are used today. Examples are narrow lanes or low load-carrying capacity. 12

(1). 13

In the United State, Bridge deficiency is determined using the Recording and Coding Guide for 14

the Structure Inventory and Appraisal of the Nations Bridges (2). The National Bridge Inventory (NBI) 15

keeps a record of the scores that have been produced by local and state agencies. A bridge is considered 16

structurally deficient (SD) if any of the conditions in Table 1 are met. 17

Table 1. Structurally deficient NBI scoring categories (4). 18

Categories NBI Item Number Deficiency Score Deck Condition 58 4 Superstructure 59 4 Substructure 60 4 Structural Evaluation 67 2 Waterway Adequacy 71 2

Likewise, a bridge is categorized as Functionally Obsolete (FO) if any of the conditions in Table 19

2 are met. 20


4

Table 2. Functionally obsolete NBI scoring categories (4). 1

Categories Description NBI Item Number Deficiency Score Structural Evaluation (S) Capacity evaluation 67 3 Waterway Adequacy (W) Flood evaluation 71 3 Deck Geometry (D) Bridge width vs. ADT and # of lanes 68 3 Under Clearances (U) Height over roadway beneath 69 3 Approach Roadway Alignment (A) Angle between bridge and approach 72 3

Based on NBI standards, any bridge found to be structurally deficient supersedes a functionally 2

obsolete classification. A bridge found to be functionally obsolete may be due to low scores in 3

the structural evaluation (S) or under clearances (U), which obstruct large heavy vehicles, 4

requiring them to choose an alternate route. This obstruction will only minimally interfere in the 5

daily flow of traffic for the average passenger vehicle. Bridges classified as functionally obsolete 6

due to deck geometry (D), approach roadway alignment (A), or waterway adequacy (W) have 7

geometries or obstructions which cause a reduction in speed. Roadway geometry that differs 8

from base condition has been shown to cause a reduction in free flow speed (3). In the presence 9

of other vehicles, this slowdown can reduce the level of service for the bridge. This reduction in 10

service is considered congestion. A bridge determined to have poor deck geometry (D) does not 11

have adequate width as compared to Average Daily Traffic (ADT) and lane number 12

requirements. Poor deck geometry can also be a function of insufficient vertical clearance. A 13

bridge with poor roadway alignment (A) is expected to require a speed reduction upon approach 14

to improve throughput. A bridge with poor waterway adequacy (W) frequently floods, making it 15

impassable during certain periods. All of these conditions, except lack of vertical clearance, are 16

expected to result in a reduction in speed which can lead to congestion. An analysis of the 1992 17

NBI showed the individual leading cause for deficiency (including both structurally deficient and 18

functionally obsolete bridges) was deck geometry (4). 19


5

While the rating factors for deck geometry, road alignment, and to some extent 1

waterway adequacy, are meant to represent areas where congestion might occur, they are in 2

themselves not measures of congestion. The NBI uses ADT and bridge and roadway geometries 3

to model conditions where congestion is likely. In the past it has not been economically feasible 4

to directly measure and quantify congestion. With the recent development of regionally 5

dispersed commercially available anonymous probe vehicle speed data, it is becoming possible 6

to spatially and temporally evaluate congestion occurrence (5). Recent studies have applied 7

performance measures based on this data to evaluate highway corridors, crash incidents, and 8

construction projects (6, 7, 8, and 9). 9

This paper presents an evaluation of congestion for bridges categorized as functionally 10

obsolete due to deck geometry in Burlington County, New Jersey. The evaluation consists of 11

congestion metrics calculated from crowd sourced anonymous probe vehicle data. The 12

congestion metrics presented are used to determine the presence, time, and the intensity of 13

congestion at, or before, a functionally obsolete bridge. These congestion values are then 14

compared to the NBI rankings to determine if the current bridge ranking parameters effectively 15

convey congestion, and therefore functional obsolescence. 16

BURLINGTON COUNTY NBI DATA 17

Burlington County, New Jersey reported 331 bridges in the 2013 NBI (Figure 1). Of the 18

331 bridges, 14 can be classified as structurally deficient and 112 can be classified as 19

functionally obsolete. Approximately 38% of the bridge structures in Burlington County are 20

deficient in some way, which is 13% higher than the national average. The largest cause for 21

functional obsolescence is deck geometry (69 bridges) followed by insufficient under clearances 22

(39 bridges). 23

1

2

3

4

5

6

7

8

9

10

11

12

13

Bechtel et

(deck geo

the flow

bridges m

Traffic M

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Many of

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T

indicated

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The bridges

ometry). The

of traffic by

meet this req

Message Cha

data. Of the 7

the bridges

way bridge p

in some wa

Fig

Table 3 illustr

d by SD whil

cy is given ei

considered

ese bridges w

y limiting the

quirement for

annel (TMC)

70 bridges, o

identified in

population is

y (4).

gure 1. NBI

rates the NB

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ither by a D

in this study

were chosen

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unctionally o

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bridge must

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patially loca

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obsolete due

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New Jersey.

tructural De

The reason f

Clearances,

TRB #15

to their wid

cted to impe

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adjacent to a

using probe

MCs (Table 3

ally about ha

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for the

or a DU for

-1947

dth

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alf of

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8

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Bechtel et

both. All

and none

these brid

serviceab

deck con

68), unde

(NBI Item

STRANE

factor att

permitted

the requi

high func

yearly co

Fig

t al.

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e of the deck

dges should

bility and fun

ndition (NBI

er clearance

m 72), ADT

ET Highway

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red traffic vo

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ongestion ho

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7

functionally

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ay adequacy

of lanes (NB

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se values are

to be studied

y obsolete du

nsufficient v

. Table 3 giv

BI. This ratin

I Item 67), d

(NBI Item 7

BI Item 28),

vertical clear

pacity and cle

termine if the

maximum of

estion speed

e explained i

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vertical cleara

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ng is evalua

deck geomet

71), approac

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rance (NBI It

earances for

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ton County, N

TRB #15

eck geometry

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try (NBI Item

ch road align

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tem 53). The

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nd the total

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New Jersey.

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ate

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8

Table 3. Functionally obsolete bridges in Burlington County, New Jersey. 1

Structure Number Deficiency

Serviceability and Functional Obsolescence

Congestion Speed

Threshold (MPH)

Congestion Hours

314154 FO-D 26 36 56.75

314155 FO-D 25 36 224.75

327153 FO-DU 22 47 34.50

327173 FO-D 25 31 48.00

327174 FO-D 24 47 26.25

328157 FO-D 24 31 7.75

328169 FO-D 26 48 120.00

3000004 FO-DU 22 25 25.25

3000007 FO-D 26 25 0.00

03C3105 FO-D 25 15 0.75

03C3220 FO-D 25 29 23.25

03C3600 FO-D 26 27 2.50

03C4004 SD/ FO-D 19 28 1.00

03C4130 SD/ FO-D 24 26 1.25

03C5780 FO-D 24 27 17.5

03D0360 FO-D 25 28 0.75

03D3015 FO-D 25 32 0.50

03D3063 FO-D 20 23 3.00

03D3068 FO-D 26 27 0.00

03D4100 FO-D 26 14 11.50

03D4260 FO-D 26 20 2.00

03D4270 FO-D 24 25 0.50

03D4560 FO-D 20 33 0.00

03D4570 FO-D 26 33 0.00

03D4870 FO-D 25 25 18.75

03D4900 FO-D 25 18 15.50

03D5110 FO-D 25 23 2.75

03D5250 FO-D 25 25 14.50

03E4550 SD/ FO-D 22 21 75.50

03G3900 FO-D 25 27 0.00

03H4100 FO-D 26 33 6.25

03H8001 SD/ FO-D 24 35 0.00

03H8520 FO-D 25 34 0.00

03H8620 FO-D 24 28 4.00

M033940 FO-DU 21 23 11.25

M050950 FO-D 24 46 31.00

M055100 FO-DU 22 28 28.75


9

CONGESTION EVALUATION 1

Congestion at the bridge structures is determined using crowd sourced anonymous probe 2

vehicle data. This data comes in the form of time stamped speed data for each TMC. For this 3

study, the entire year of 2013, consisting of approximately 35 million speed records, was 4

analyzed for each bridge in both directions. The data is sorted into 15-minute bins for each day 5

of the year. Congestion is tied to a reduction in speed. In this study significant congestion was 6

assumed to occur when speeds dropped below a defined threshold. Previous studies had used 7

45mph as the congestion threshold (6). For this study, the congestion threshold speed was based 8

on the 70th percentile space mean speed (SMS) for each TMC, and it was calculated using speed 9

data between the hours of 0200 and 0600 each day (Table 3). Congestion hours are determined 10

using a binary indicator, where each SMS is compared to the congestion threshold speed 11

calculated for each TMC. If the SMS falls below the threshold, the 15-minute bin it is assigned a 12

value of 1; if it is above the speed value it is assigned a value of 0. The resulting values can then 13

be summed and divided by 4 to calculate the congestion hours. The congestion hours can be 14

aggregated by hour, day, month, or year. Table 3 gives the yearly congestion hours for the 15

functionally obsolete bridge structures. The monthly data is represented graphically in the 16

stacked bar graph in Figure 3. The top 10 NBI bridges are compared to the calculated congestion 17

hours shown in Table 4. 18

The bridge structures in Figure 3 are organized in order of ascending congestion hours. 19

Seven of the bridges studied experienced no congestion, despite being functionally obsolete due 20

to their deck geometry. This shows that a rating of functionally obsolete due to deck geometry is 21

not an absolute indicator of congestion. The bridge with the worst congestion is bridge 314155. 22

This structure experienced 224.75 congestion hours for the year of 2013, and these congestion 23


10

hours are consistent through each month. If there are assumed to be 1500 business related travel 1

hours a year (250 work days and 6 peak hours a day) all but the worst bridges are congested less 2

than 10% of the time. The 10 bridges with the worst NBI serviceability and functional 3

obsolescence ratings are also labeled in Figure 3. Only 5 out of the top 10 worst bridges in 4

Burlington County, as ranked by the NBI, appear in the top 10 most congested bridges. There is 5

a noticeable difference between the rating in the NBI Serviceability and Functional Obsolescence 6

Rating and where congestion is observed. 7

Table 4. Ten bridges with lowest NBI Serviceability and Sufficiency Rating 8

NBI Rank

Structure Number Deficiency

Serviceability and Functional Obsolescence

Congestion Speed

Threshold (MPH)

Congestion Hours

#1 03C4004 SD/ FO-D 19 28 1.00 #2 03D3063 FO-D 20 23 3.00 #2 03D4560 FO-D 20 33 0.00 #4 M033940 FO-DU 21 23 11.25 #5 327153 FO-DU 22 47 34.50 #5 3000004 FO-DU 22 25 25.25 #5 03E4550 SD/ FO-D 22 21 75.50 #5 M055100 FO-DU 22 28 28.75 #9 327174 FO-D 24 47 26.25 #9 328157 FO-D 24 31 7.75


11

Figure 3. Monthly congestion hours for 2013. 1

0 50 100 150 200 250

314155

328169

03E4550

314154

327173

327153

M050950

M055100

327174

3000004

03C3220

03D4870

03C5780

0384900

0385250

0384100

M033940

328157

03H4100

03H8620

03D3063

03D4260

03C3600

03D4260

03C4130

03C4004

03C3105

03D0360

03D3015

03D4270

3000007

03D3068

03D4560

03D4570

03G3900

03H8001

03H8520

Congestion Hours

Bri

dge

Num

ber

January

February

March

April

May

June

July

August

September

October

November

December

(NBI Rank #1)

(NBI Rank #2)

(NBI Rank #2)

(NBI Rank #4)

(NBI Rank #5)

(NBI Rank #5)

(NBI Rank #5)

(NBI Rank #5)

(NBI Rank #9)

(NBI Rank #9)

No Congestion Hours


12

BRIDGE MANAGEMENT 1

The goal of bridge management is to get the best return on investment. In this case, the 2

return is improved mobility and travel time reliability. This can mean a bridge can be 3

strengthened to carry larger loads and additioinal vehicles, or it can be reconfigured to improve 4

traffic flow. Ultimatly, there are three courses of action that an be taken when evaluating a 5

structure: 6

1. Do nothing 7

2. Repair or retrofit the existing structure 8

3. Replace the structure. 9

To demonstrate how congestion analysis can be used as a tool for the management of 10

bridges, three sample structures will be evaluated. These three structures are Bridge 03C4004 11

(most deficient bridge by NBI Rank, Table 4 ), Bridge 03E4550 (best agreement between 12

congestion analysis and NBI, Table 4), and Bridge 314155 (highest amount of measured 13

congestion Table 3). The structures will be evaluated individually, incorporating their structural 14

condition into the process. 15

Bridge 03C4004 16

Bridge 03C4004 is structurally deficient and functionally obsolete due to its deck 17

geometry. It has a structural evaluation of 2 out of 10, and a serviceability and functional 18

obsolecence rating of 19 out of 30. Bridge 03C4004 carries a city street across the Rancocus 19

Creek; it was constructed in 1909 and improved upon in 2007. Figure 4a shows a close-up aerial 20

view of the bridge. The bridge serves to connect two residential areas. Figure 4b shows a more 21

expansive aerial view of the bridge and its surroundings. Directly southeast of the bridge is I-22

295. Farther to the northwest and southeast, routes 130 and 38 both cross the Rancoucus Creek. 23

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Bechtel et

F

congestio

volumes.

63%. Ba

If the bri

impact. I

be to stre

there is n

there is le

to safety

Bridge 03

B

geometry

a) Clo

t al.

rom the con

on hour per y

. This is in c

ased on its pr

dge has vehi

f the bridge

engthen or re

no need to ex

ess of a need

concerns.

3E4550

Bridge 03E45

y. It has a str

se up view of

4

Figure

ngestion anal

year (Table 3

ontrast to th

roximity to I

icle weight r

were to beco

epair the exis

xpand the bri

d to replace t

550 is structu

ructural eval

f bridge

e 4. Aerial vi

lysis, it has b

3). This bein

he Serviceabi

I-295 there i

restrictions p

ome structur

sting structu

idge to carry

the bridge. T

urally defici

luation of 2 o

13

iew of Bridge

been shown t

ng the case, t

ility and Fun

is no need fo

plassed on it

rally unsafe,

ure. Due to th

y more volum

The only rea

ent and func

out of 10, an

b) Brid

RT 1

03C4

e 03C4004 (1

that Bridge 0

the bridge ad

nctional Obs

or the bridge

, there will n

, the recomm

he low numb

me. If there i

son to replac

ctionally obs

nd a servicea

dge location r

130

4004

10)

03C4004 ha

dequatly han

solecence Ra

to carry hea

not be a larg

mendation fo

ber of conge

is no need fo

ce the bridge

solete due to

ability and fu

related to I-29

RT 38

TRB #15

as a total of o

ndles traffic

ating which i

avy truck tra

e economic

or action wou

estion hours,

or expansion

e would be d

o its deck

unctional

95

I-295

-1947

one

is

affic.

uld

n

due

1

2

3

4

5

6

7

8

9

10

11

12

13

15

Bechtel et

obsolecen

across th

shows a c

of the bri

Fort Dix.

determin

per mont

traffic (1

decreases

speed bet

slowdow

indicator

it is caus

t al.

nce rating of

e Rancocus

close-up aer

idge is locate

. Bridge 03E

ne when thes

th over the en

1). In Figure

s in both the

tween 10 an

wn, the fact th

r that the brid

ing congesti

a) Close

f 22 out of 3

Creek; it wa

rial view of t

ed a signaliz

E4550 experi

e congestion

ntire day wa

e 6, as the co

e AM and PM

d 11 AM. W

hat there is s

dge is influe

ion, it would

Figure

up view of br

30. Bridge 03

as constructe

the bridge, an

zed intersecti

ienced 75.5

n hours occu

as created; th

olor darkens,

M peak hour

While the sign

slowdown an

ncing traffic

d be a good c

18

e 5. Aerial vi

ridge

14

3EA4550 ca

ed in 1932 an

nd Figure 5b

ion, and loca

congestion h

urred, a conto

his diagram i

, the travel s

s. The south

nalized inter

nd congestio

c. Since this

candidate for

iew of Bridge

0

b) B

arries Burling

nd improved

b shows an e

ated off of th

hours in 201

our diagram

is shown in F

speed decrea

hbound lane

rsection may

on in both dir

bridge is bo

r replacemen

e 03E4550 (1

03E4550

Bridge locatio

gton County

d upon in 19

expanded vie

he figure to t

3 (Table 4).

of the avera

Figure 6 for

ases. There a

experiences

y cause some

rections wou

oth structural

nt.

12)

For

Inte

on related to

TRB #15

y Route 616

77. Figure 5

ew. To the s

the northeas

In order to

age traffic sp

both lanes o

are clear

its slowest

e of the

uld be an

lly deficient

rt Dix

rsection

intersection

-1947

5a

outh

st is

peed

of

and


15

a) Northbound lane 1

b) Southbound lane 2

Figure 6. Average monthly travel speed per time of day for Bridge 03E4550 3

Bridge 314155 4

Bridge 314155 carries Southbound New Jersy Route 73, a major arterial connecting 5

Philadelphia to I-295 and the New Jersey Turnpike, over New Jersey Route 38 (Figure 7). The 6

Time of Day

Mon

th

Miles per H

our

200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400January

February

March

April

May

June

July

August

September

October

November

December

22

24

26

28

30

32

34AM Peak7-10 AM 4-7 PM

PM Peak

T ime of Day

Mon

th

Miles per H

our

200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400January

February

March

April

May

June

July

August

September

October

November

December

24

25

26

27

28

29

30

31

32

33AM Peak

4-7 PMPM Peak

7-10 AM

1

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

Bechtel et

bridge ha

rating of

out of an

and Func

with Brid

(Figure 7

are clear

hours tha

heading t

A

congestio

causing t

commerc

signal op

over the b

3

t al.

as a structura

25 out of 30

ny bridge stu

ctional Obso

dge 314154,

7a). Figure 8

slowdowns

an the AM h

toward I-295

Although Bri

on could pos

this congesti

cial shopping

peration at th

bridge. Befo

314155

a) Close u

al evaluation

0. In 2013, th

died (Table

lecence ratin

which has a

shows the a

during the A

ours, presum

5 or the Turn

Figur

dge 314155

ssibly be due

ion. There is

g center, as w

hese points c

ore a recomm

up view of bri

n of 6 out of

he bridge exp

3). Despite t

ng of the thr

a similar des

average mon

AM and PM

mably from p

npike.

14

re 7. Aerial v

is structural

e to the bridg

a signalized

well as a sig

ould be caus

mendation fo

idge

16

10, and a se

perienced 22

this finding,

ee bridges e

ign, but only

nthly speed p

peak hours.

people leavin

view of Bridg

lly adequate,

ge deck geom

d intersection

nalized inter

sing traffic s

or the bridge

I-29

Phi

b) B

erviceability

24.75 conge

it has the hi

evaluated. Br

y experience

per time of d

There is gre

ng work in th

ge 314155 (13

, it is experie

metry. How

n just south

rsection on E

slowdown th

e is made, it w

31

95 and NJ Tur

iladelphia

ridge location

and function

estion hours;

ighest (83%)

ridge 314155

ed 56.75 con

day for Bridg

eater slowdo

the greater P

3)

encing cong

wever, other f

on New Jers

East New Jer

hat impacts s

would be pru

14155

rnpike

n related to Ph

TRB #15

nal obsolece

this is the m

) Serviceabil

5 runs parrel

ngestion hour

ge 314155. T

own in the PM

hiladelphia a

gestion. This

factors may

sey RT 73 ne

rsey RT 38.

speed of vehi

udent to per

hiladelphia

-1947

ence

most

lity

llel

rs

There

M

area

be

ear a

The

icles

form


17

a traffic study of the general area. If they are creating the traffic slow down, the signals can 1

possibly be adjusted to mitigate congestion in the area. Adjusting signal timing is more cost 2

efficient than expanding the bridge. 3

Figure 8. Average monthly travel speed per time of day for Bridge 314155 4

CONCLUSIONS AND FUTURE WORK 5

The evaluation of bridge structural integrity and functional obsolesce is used as a means 6

to determine where capital improvements should be focused. Under the current system, a 7

bridge’s functional obsolesce is partially based on NBI criteria that would indicate a bridge’s 8

inability to effectively provide the necessary capacity for the current traffic volume. The lack of 9

traffic capacity is therefore expected to cause congestion at the bridge structures. This study 10

applied anonymous crowd source probe vehicle data congestion analysis methodologies that are 11

currently used to evaluate roadway performance to a sample set of bridge structures found to be 12

functionally obsolete as defined by NBI. All of the bridges evaluated were functionally obsolete 13

Time of Day

Mon

th

Miles per H

our

200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400January

February

March

April

May

June

July

August

September

October

November

December

34

36

38

40

42

44

46

48

50

52

54AM Peak7-10 AM

PM Peak4-7 PM


18

due to their deck geometries with no bridges having vertical clearance issues. The study found 1

that although the NBI rating showed that a bridge should incur congestion; this was not 2

necessarily the case. 3

In total 37, functionally obsolete bridges in Burlington County, New Jersey were 4

evaluated using probe vehicle data for the 2013 calendar year. Of the 37 bridges, 7 experienced 5

no congestion hours at all. Twenty-eight bridges experienced less than 100 hours of congestion 6

for the year, and only two bridges experienced more than 100 congestion hours with the 7

maximum being 224.75 hours. Of the 10 worst ranked structures based on the NBI, only 5 8

appeared in the 10 bridges with the worst measured congestion (Figure 3). The top 2 bridges 9

found to have the highest measured congestion were not ranked in the NBI’s top 10 worst 10

structures (Figure 3/ Table 4). 11

An alternative bridge assessment methodology that combines the measured congestion 12

and travel speed information obtained from probe vehicle data and the NBI structural rating was 13

proposed. This new methodology was then used to make recommendations for three sample 14

bridges. The congestion and speed data proved to provide insight into how the bridge is 15

functioning beyond the NBI Serviceability and Functional Obsolescence rating. It helped provide 16

a clear picture as to which actions to take when determining if repair or replacement were 17

necessary. The next step in vetting this analysis method is to evaluate all of the bridges agency 18

wide, not just the structures determined to be functionally obsolete. This will give a clear picture 19

of how well the NBI ranking picks up bridges which are not adequately handling traffic 20

demands. Also, an economic factor will be tied to congestion hours to evaluate the impact of 21

increased congestion. This factor can then be weighed against the cost of multiple types of 22

corrective measures to evaluate their cost-benefit relationships. 23


19

ACKNOWLEDGMENTS 1

The authors would like to thank the Coordenação de Aperfeiçoamento de Pessoal de 2

Nível Superior (CAPES) Foundation - Ministry of Education of Brazil for providing funding for 3

our undergraduate researchers. The contents of this paper reflect the views of the authors, who 4

are responsible for the facts and the accuracy of the data presented herein, and do not necessarily 5

reflect the official views or policies of the sponsoring organizations. These contents do not 6

constitute a standard, specification, or regulation. The speed data and segment information used 7

in this report was obtained from INRIX Inc. 8


20

LIST OF FIGURES 1

Figure 1. NBI bridges in Burlington County, New Jersey 2

Figure 2. Functionally obsolete bridges to be studied in Burlington County, New Jersey 3

Figure 3. Monthly congestion hours for 2013 4

Figure 4. Aerial view of Bridge 03C4004 5

Figure 5. Aerial view of Bridge 03E4550 6

Figure 6. Average monthly travel speed per time of day for Bridge 03E4550 7

Figure 7. Aerial view of Bridge 314155 8

Figure 8. Average monthly travel speed per time of day for Bridge 314155 9

LIST OF TABLES 10

Table 1. Structurally deficient NBI scoring categories 11

Table 2. Functionally obsolete NBI scoring categories 12

Table 3. Functionally obsolete bridges in Burlington County, New Jersey 13

Table 4. Ten Bridges with lowest NBI Serviceability and Sufficiency Rating 14


21

REFERENCES 1

1. ASCE. (2013). Report Card for America’s Infrastructure, 2

http://www.infrastructurereportcard.org/bridges/ (July 9, 2014) 3

2. Recording and Coding Guide for the Structure Inventory and Appraisal of the Nations’ 4

Bridges (1995). Bridge Management Branch, Bridge Division, Federal Highway 5

Administration, Washington D.C. 6

3. National Research Council (2010). Highway Capacity Manual HCM 2010 Transportation 7

Research Board, Washington D.C. 8

4. Dunker, K.F., Rabbat, B.G. (1995). Assessing Infrastructure Deficiencies: The Case of 9

Highway Bridges Journal of Infrastructure Systems Vol. 1(2). Pgs 100-119. 10

5. Brennan, T. M., Day, C.M., Remias, G.M. Horton, D.K., Cox, E.D., Bullock, D. M. (2014). 11

Alternative Performance Measures and Weighting for Quantifying Spatial and Temporal 12

Congestion using Probe Data. ITS 21st World Congress 13

6. Remias S, Brennan T, Grimmer G, Cox E, Horton D, Bullock D. 2011 Indiana Interstate Mobility 14

Report - Full Version. West Lafayette, Indiana: Purdue University, Indiana Mobility Reports; 2012. 15

Report No.: ISBN: 978-1-62260-209-4. 16

7. Remias S, Brennan T, Day C, Summers H, Cox E, Horton D, Bullock D. 2012 Indiana Mobility 17

Report - Full Version. West Lafayette, Indiana: Purdue University, Indiana Mobility Reports; 2013. 18

Report No.: ISBN: 978-1-62260-257-5. 19

8. Lomax, T., D. Shrank, B. Eiselee. 2012 Annual Urban Mobility Report. College Station, Texas; The 20

Texas A&M University System, Texas A& M Transportation Institute, 2012. 21

9. Lomax, T., D. Shrank, B. Eiselee. 2011 Urban Mobility Report Powered by INRIX Traffic Data. 22

College Station, Texas; The Texas A&M University System, Texas A& M Transportation Institute, 23

2011. 24

10. Google Earth. Longitude: 39.997364, Latitude: -74.87251944. Release 7.1.2.2041 Accessed, July 25, 25

2014. 26

11. Brennan, T.M, D.M. Bullock, “Regional Travel Time Reliability” The 5th International Symposium 27

on Transportation Network Reliability (INSTR2012), 18-19 December 2012, Hong Kong. 28


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