This document provides an introduction to adaptive signal control systems. It discusses how Sain Associates got involved through an FHWA initiative and how they recommended the SCATS system to ALDOT. It then describes how SCATS and other adaptive systems work using real-time traffic data to optimize signal timing. Graphs show reductions in delay compared to non-adaptive systems. Finally, it provides an update on ALDOT's initial implementation projects in Montgomery, Birmingham, and Huntsville.

1. AN INTRODUCTION TO

2. Outline
 Example of systems & definition
 How did Sain get involved?
 Scan Tour & ALDOT’s reaction
 How it works
 Different systems
 Graphs
 Status of ALDOT Projects
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3. Example of Systems
 InSync
 SCATS
 SCOOT
 ACS Lite
 Several others…
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4. Definition
 Traffic signal timing control technology
that has the ability to utilize real-time
traffic information to adjust traffic signal
system timings in an effort to reduce
congestion and delay.
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5. How did we get involved?
 FHWA Every Day Counts (EDC)
 EDC is designed to identify and deploy
innovation aimed at shortening project delivery,
enhancing the safety of our roadways, and
protecting the environment.
 Adaptive Signal Control Subcommittee
 Members consist of ALDOT, FHWA, City of
Montgomery, and Sain Associates
 Sain is the only consultant on the committee!
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6. Committee Members
 FHWA
 Jeff Dogan
 ALDOT
 Stacey Glass, Gary Moore, Kim Norton,
Robert Blankenship
 City of Montgomery
 Bubba Bowden, Tim Foster
 Sain Associates
 Jeff Stephenson
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7. Scan Tour: Sep. 12-14
2011
 Visited 3 locations in GA
 (1) City of Alpharetta
3 1
○ Tested InSync, SCOOT 2
 (2) Columbia County
○ Running InSync
 (3) Cobb County
○ Running SCATS
 Group recommended SCATS to ALDOT
front office for initial implementation in AL
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8. ALDOT Initial
Implementation
 (1) Montgomery
 Southern Boulevard/Eastern Boulevard
 (2) Birmingham area
 US-280 3
2
1
 (3) Huntsville
 Governors Drive
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9. Signal Timing Methods
 Free/Isolated
 Time Based Coordination
 Traffic Responsive
 Adaptive Control
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10. Adaptive Control – How?
 The tactics of different systems work
different ways, however…
 The general idea is that data being
collected by the vehicle detectors is
being used in real time to determine the
signal timings.
 Wide range of % reductions in delay
reported by various adaptive signal
controls
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11. SCOOT
 Split Cycle Offset Optimization Technique
 Used worldwide, a lot in Great Britain
 Uses data from advance detectors, models
progression from detector to stopline
 Factors for queuing
 Central server and on-street firmware
 Requires communication
 Need computer programming background
to understand system commands required
to operate and maintain the system
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12. InSync
 Rhythm Engineering
 Plug-and-play
 Controller set in free mode using
existing firmware
 Detector data taken, analyzed, and
sends calls to controller
 Requires communication
 Newer program, still customizing on the
fly to meet customers needs
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13. SCATS
 Sydney Coordinated Adaptive Traffic System
 Originated in Australia, found worldwide,
about 1/3 are in Australia
 Uses stopline video detection (6 x 15 zones)
to detect/measure gaps
 Central server selects pre-determined
cycle/split/offsets
 Communication required
 Synchro still needed!
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15. SCATS (Cont’d)
 Certain models of controller are required to
run SCATS
 US-280 getting Eagle M50 model
 Governors Drive getting 2070
 SCATS firmware installs alongside
traditional firmware on street controller
 Any mode of detection works, but video is
recommended
 Engineering design element of project is
generally required for implementation of
equipment modifications
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16. “Never retimed” to
“Adaptive”
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17. “Retimed” to “Adaptive”
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18. Savings
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19. Adaptive vs. TOD
140
120
100
80
Adaptive Cycle
60 TOD Cycle
40
20
0
12 2 4 6 8 10 12 2 4 6 8 10 12
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20. ALDOT Project Status
 Montgomery
 PS&E held Jan 4
 May 25 2012 Project Letting
 Birmingham
 PS&E is Jan 26
 May 25 2012 Project Letting
 Huntsville
 PS&E TBD (Feb 8 or Feb 9)
 May 25 2012 Project Letting
 ALDOT Transportation Director wants all
implemented by June 2012
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