using high-resolution data to evaluate arrival on green...using high-resolution data to evaluate...
TRANSCRIPT
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
9/19/2017 1
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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