Using High-Resolution Data to Evaluate Arrival on Green

Technical Session 9Real Results in the Age of Performance-Based Operations

Presented by: Joshua Pilachowski, PE, PhD

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Outline of Presentation

• Traditional Arterial Performance Measures

•Next Generation Arterial Performance Measures

•Purdue Diagrams

•Accurately Evaluating Arrival on Green

•Case Study: Fremont Boulevard Adaptive Evaluation

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Traditional Arterial Performance Measures

• Data Sources were primarily small sample size

• Tach runs

• Highly detailed trajectory

• Small portion of flow

• High cost for labor and processing

• Volume counts (Turning movement and segment volume)

• Full description of turning movements

• Enough data to simulate performance

• High cost

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Next Gen Arterial Performance Measures

• Data Sources become comprehensive

• Bluetooth Travel Time

• Data collected 24/7

• Larger portion of flow

• Filtering required

• High Resolution Volume Data

• Data collected 24/7

• Accuracy dependent on lane configuration and detector presence

• Usually not sufficient data for modeling

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Detector

A

Detector

B

Intermediate

Destination

Purdue Coordination Diagrams

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• Visualization for corridor coordination and smoothness of flow

• Maps vehicle arrivals to signal phase

• Reports automatically generated by signal management software

Effective Green Time

Effective Red Time

Single Cycle length

Sin

gle

Cyc

le l

en

gth

Begin of Green

Begin of Red

Purdue Coordination Diagrams

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Purdue Coordination Diagram

• Benefit – Easy to spot issues with coordination and platooning

• Benefit – Effective performance monitoring

• Difficulty – Black box reporting hides potential inaccuracies

• Phase change for vehicles between the detector and intersection

• Persistent or long queues

• Harder to evaluate changed timing patterns

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Detector Location

• Detector located too far upstream can over-represent arrival on green

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Stop-bar Detector

Advance Detector

Translate the begin of red

time back to the detector

location at freeflow speed

Detector Location

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Stop-bar Detector

Advance Detector

• Detector located upstream of regular queue length

Vehicle arriving at back of

queue will not pass the

detector until the queue

discharges

Detector Location

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0

2

4

6

8

10

12

14

16

18

7:00:00 AM 7:20:00 AM 7:40:00 AM 8:00:00 AM 8:20:00 AM 8:40:00 AM

Arrivals on Y/R

Queue overflow

No Queue overflow

Purdue Coordination Diagrams

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Before/After Evaluation

• Changes in arrival on green percentage can be indicative of changes in demand or land use

• Automatic reporting of MoE’s by timing pattern does not allow for changes in peak times or adaptive timing

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AM

Peak

PM

Peak

Morning

Free

Evening

FreeMidday

School

Pickup

Adaptive Timing

Recreate Purdue Coordination

Diagram using detector hits and

phase termination report

Case Study – Fremont Boulevard

• Funded by MTC’s Next Generation Arterial Operations Program (NGAOP) Grant

• Implementation of adaptive signal timing for 9 signalized intersections along a 2.2 mi corridor

• DKS contracted to perform theBefore/After evaluation

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Case Study – Fremont Boulevard

• Advance detectors located 250 upstream of the signal

• Shared lanes on most minor streets

• Queues during peak period not observed to extend past advance detectors

• “Before” timing periods did notmatch up with “After “adaptive periods

• Adaptive timing generally resultedin increased arrival on green

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Purdue Diagrams

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0

20

40

60

80

100

120

140

160

180

7:00:00 AM 7:15:00 AM 7:30:00 AM 7:45:00 AM 8:00:00 AM 8:15:00 AM 8:30:00 AM 8:45:00 AM 9:00:00 AM

Tim

e (

Se

con

ds)

Time

Purdue Coordination Diagram (Fremont/Tamayo on March 6, 2017, Phase 6)

Yellow

Red

Green

Detectors 8,9

AoG = 80%

Case Study – Fremont Boulevard

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+2%

-10%

+6%

+12%

+10%

+1%

+3%

+8%

+2%

+6%

-17%

+10%

+15%

-4%

+1%

+13%

+7%

+4%

AM Peak (7:30am-8:30am)Includes School Drop-off

Initial Percent Arrival

on Green

Decrease in Percent

Arrival on Green

Increase in Percent

Arrival on Green

School Location

Questions?

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