Anonymous Probe Vehicle Data Andrew J. Bechtel PhD Thomas M. - - PowerPoint PPT Presentation

Evaluation of Bridge Functional Obsolescence Using Congestion Performance Measures Determined from Anonymous Probe Vehicle Data

Andrew J. Bechtel PhD Thomas M. Brennan Jr. PhD, PE

Moving Ahead for Progress in the 21st Century Act

• MAP 21

– Seeks to implement Risk Based Asset Management of US Infrastructure

• Risk Based Asset Management involves identifying,

assessing, and minimizing unacceptable risk

– Loss of Life – Loss of Money

Structural ¡Failure: ¡ Structurally ¡Deficient ¡ Poor ¡Func3on: ¡ Func3onally ¡Obsolete ¡

National Bridge Inventory

New ¡Jersey,310153,Route ¡Carried ¡on ¡Structure,3,1,70,0,3,5,68610,'BEAR ¡SWAMP ¡RIVER',,'NJ ¡70 ¡','2.5 ¡MI ¡E ¡OF ¡70-­‑541 ¡INTER.',99.99,26.454,1,00000070__, 0,39534360,74464502,6,3,1,1,14,1931,2,0,22775,2012,6,17.3,0,0,0,0,0,0,0,5,0,0,0,A,1,5,5,1,0,0,1,0,17.3,6.4,6.7,0,0,17.3,18.3,99.99,N,0,N,30.5,0,6,7,6,6,N,1,99.9,1,99.9,6,9,N,5,9,8,,,0,112,24,N ¡ ¡,N ¡ ¡,N ¡ ¡,,,,,,,,,,, 0,N,2,,1,0,1983,1,1,0,1,4,0,,Y,5,27330,2032,,N, ¡, ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡ ¡, ¡, ¡ ¡, ¡, ¡ ¡ ¡ ¡, ¡ ¡ ¡ ¡ ¡ ¡ ¡, ¡, ¡ ¡, ¡ ¡, ¡,0, ¡ ¡ ¡ ¡ ¡,90.6,0 ¡

• Database Maintained by FHWA

– Location data – Geometric data – Traffic data – Conditional assessment data

Functional Obsolescence

• State where a bridges no longer meets the current

standards for design and performance

Categories NBI ¡Item ¡Number Deficiency ¡Score Structural ¡Evalua:on ¡(S) 67 ≤ 3 Waterway ¡Adequacy ¡(W) 71 ≤ 3 ¡ Deck ¡Geometry ¡(D) 68 ≤ 3 Under ¡Clearances ¡(U) 69 ≤ 3 Approach ¡Roadway ¡Alignment ¡(A) 72 ≤ ¡3

Can’t ¡carry ¡enough ¡load ¡ Floods ¡ Not ¡wide ¡enough ¡for ¡volume ¡ Not ¡high ¡enough ¡ Traffic ¡must ¡slow ¡at ¡approach ¡

Structurally Deficiency

¡Categories NBI ¡Item ¡Number Deficiency ¡Score Deck ¡Condi:on ¡ 58 ≤ ¡4 Superstructure ¡ 59 ≤ 4 Substructure 60 ≤ ¡4 Structural ¡Evalua:on 67 ≤ 2 Waterway ¡Adequacy 71 ≤ ¡2

• State that requires significant maintenance,

rehabilitation, or replacement due to deterioration or damage of main load carrying elements

NBI Sufficiency Rating

Structural ¡ Adequacy ¡and ¡ Safety ¡ 55% ¡ Serviceability ¡ and ¡Func3onal ¡ Obsolescence ¡ 30% ¡ Essen3ality ¡for ¡ Public ¡Use ¡ 15% ¡

Objectives and Scope

• Use crowd sourced anonymous probe vehicle data to

measure and evaluate congestion at bridges in Burlington County, New Jersey considered to be Functionally Obsolete

• Use the congestion analysis as a bridge management

tool

Burlington County, NJ

• 7% Structurally Deficient
• 38% Functionally Obsolete

– 21% Deck Geometry – 12% Under Clearance – 5% Other

Burlington County, NJ

• 37 bridges evaluated

– Located adjacent to TMC (Traffic Message Chanel) – Deficient due to Deck Geometry – Many located on county roads

Burlington County, NJ

NBI ¡Rank Structure ¡ ¡ ¡Number Deficiency Serviceability ¡and ¡Func:onal ¡ Obsolescence ¡(Out ¡of ¡30) #1 03C4004 SD/ ¡FO-­‑D 19 #2 03D3063 ¡FO-­‑D 20 #2 03D4560 ¡FO-­‑D 20 #4 M033940 ¡FO-­‑DU 21 #5 327153 ¡FO-­‑DU 22 #5 3000004 ¡FO-­‑DU 22 #5 03E4550 SD/ ¡FO-­‑D 22 #5 M055100 ¡FO-­‑DU 22 #9 327174 ¡FO-­‑D 24 #9 328157 ¡FO-­‑D 24

Data

• Speed data is calculated from GPS Locations

– GPS is pinged entering and exiting a TMC – The time between pings is divided by the TMC length to produce space mean speed

• Time stamped speed data is reported

– Approximately 35 million speed records for the 37 bridges studied (2013).

Data Processing

• Data is sorted into 15 min bins for each day of the

year

– The data points in each bin are averaged for that 15 min period

• Congestion is tied to a reduction in speed

– Significant speed reduction was considered to be 70% of the free-flow speed – Free-flow speed was calculated for each TMC by finding the space mean speed for the year between 2AM and 6AM

Data Processing

• The data is evaluated using a binary indicator

– If the average space mean speed drops below 70% of the free- flow speed, the 15 min period is assigned a value of 1 – If the average space mean speed speed does not drop below 70% of the free-flow speed, the 15 min period is assigned a value of 0

• The binary indicators can then be summed and divided

by 4 to calculate congestion hours

– The hours can then be aggregated as desired (day, month, etc.)

Congestion Analysis

50 100 150 200 250 Congestion Hours 3 1 4 1 5 5 3 2 8 1 6 9 3 E 4 5 5 M 3 7 2 A 3 1 4 1 5 4 3 2 7 1 7 3 3 2 7 1 5 3 M 5 9 5 M 5 5 1 3 2 7 1 7 4 3 4 3 C 3 2 2 3 D 4 8 7 3 C 5 7 8 3 8 4 9 3 8 5 2 5 3 8 4 1 M 3 3 9 4 3 2 8 1 5 7 3 H 4 1 3 H 8 6 2 3 D 3 6 3 3 D 4 2 6 3 C 3 6 3 D 4 2 6 3 C 4 1 3 3 C 4 4 3 C 3 1 5 3 D 3 6 3 D 3 1 5 3 D 4 2 7 3 7 3 D 3 6 8 3 D 4 5 6 3 D 4 5 7 3 G 3 9 3 H 8 1 3 H 8 5 2 January February March April May June July August September October November December

No Congestion Hours

(1) (9)

(5) (4)

(2) (9) (5) (5) (5) (2)

• ­‑Approximately ¡258 ¡work ¡days ¡a ¡year ¡
• ­‑Approximately ¡6 ¡peek ¡travel ¡hours ¡a ¡work ¡day ¡(7AM-­‑10AM, ¡4PM-­‑7PM) ¡
• ­‑For ¡Bridge ¡314155 ¡ ¡ ¡ ¡ ¡à ¡

¡224.75/1548= ¡15% ¡ ¡

Management Strategies

• Examine three bridges to evaluate congestion analysis

as a bridge management tool

Bridge NBI Rank Congestion Rank Congestion Hours 03C4004 #1 #26 1 03E4550 #5 #3 75.5 314155

• #1

224.75

Bridge Management

• Bridge management is a complicated process

involving a complex cost and benefit analysis, but ultimately it will result in the following recommendations:

1) Do nothing 2) Repair or Retrofit the Existing Structure 3) Replace the Existing Structure

• Congestion analysis will be used to evaluate

serviceability, and the structural condition will be evaluated using the NBI rating

Bridge 03C4004 (Worst NBI Ranking)

• Constructed in 1909, and improved in 2007
• Carries a city street across the Rancocus Creek
• NBI Rating Factors

– Structural Evaluation: 2 out of 10

• Structurally Deficient

– Serviceability and Functional Obsolescence: 19 out of 30

• Obsolete due to Deck Geometry
• Congestion Analysis

– 1 Congestion Hour for 2013

Bridge 03C4004 (Worst NBI Ranking)

Bridge 03C4004 (Worst NBI Ranking)

• Conclusion

– Serves residential area – Low number of Congestion Hours (1/year) – Close proximity to I-295 lessens need to carry heavy loads

• Recommendation: Do nothing

– If structure becomes unsafe for the needs of the community, repair or retrofit

Bridge 03E4550 (Best Agreement)

• Constructed in 1932, and improved in 1977
• Carries Burlington County Route 616 across the

Rancocus Creek

• NBI Rating Factors

– Structural Evaluation: 2 out of 10

• Structurally Deficient

– Serviceability and Functional Obsolescence: 22 out of 30

• Obsolete due to Deck Geometry
• Congestion Analysis

– 75.5 Congestion Hour for 2013

Bridge 03E4550 (Best Agreement)

Best Agreement

Time of Day Miles per Hour 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 January February March April May June July August September October November December 24 25 26 27 28 29 30 31 32 33

Southbound ¡

Time of Day Month Miles per Hour 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 January February March April May June July August September October November December 22 24 26 28 30 32 34

Northbound ¡

Bridge 03E4550 (Best Agreement)

• Conclusion

– Bridge is structurally deficient – Causes congestion in both directions (75.5 CH/year)

• Recommendation: Replace

Bridge 314155 (Worst Congestion)

• Carries NJ Route 73 South connecting Philadelphia to

I-295

• Bridge 314154 carries 74 North (56.75 CH/year)
• NBI Rating Factors

– Structural Evaluation: 6 out of 10 – Serviceability and Functional Obsolescence: 25 out of 30

• Obsolete due to Deck Geometry
• Congestion Analysis

– 224.75 Congestion Hour for 2013

Bridge 314155 (Worst Congestion)

Bridge 314155 (Worst Congestion)

Time of Day Month Miles per Hour 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 January February March April May June July August September October November December

34 36 38 40 42 44 46 48 50 52 54

Bridge 314155 (Worst Congestion)

• Conclusion

– Bridge is structurally adequate – Congestion is present at bridge

• Signalized Intersections?
• Proximity to I295?
• Deck Geometry?
• Recommendation: Perform field evaluation of the

bridge and adjacent roadways

– If bridge is found to be source of congestion, widen the bridge

Conclusions

• 37 functionally obsolete bridges (due to deck

geometry) were evaluated for congestion using anonymous crowd sourced vehicle data

– FO was not necessarily and indicator of congestion

• 7 bridges experienced no congestion hours
• 28 experienced less than 100 hrs. (< 6% of peak hrs.)
• 2 bridges experienced more than 100 hrs

– Only 5 of the 10 bridges with the worst NBI ranking appeared in the 10 bridges with the worst congestion

Conclusions

• A bridge assessment methodology using the

congestion analysis was demonstrated

– The congestion analysis served to actually measure if the bridge was affecting traffic flow – Understanding if congestion actually existed made making a recommendation for a course of action clearer

Future Work

1) Accident data must be incorporated

• If a structure is causing accidents it would warrant

further investigation

2) An economic factor must be tied to congestion hours

• Provide a basis for cost benefit analyses

3) The congestion analysis needs to be performed agency wide.

• It must be used on Functionally Obsolete and Non-

functionally Obsolete bridges

Future Work

Sufficient (4266) ¡

Future Work

Sufficient (1314) ¡

Future Work

Contacts:

Andrew J. Bechtel PhD Assistant Professor Department of Civil Engineering Phone: (609) 771-2475 E-mail: bechtela@tcnj.edu Thomas M. Brennan Jr. PhD, PE Assistant Professor Department of Civil Engineering Phone: (609) 771-2798 E-mail: brennant@tcnj.edu