Freeway Adaptive system - Texas A&M University · 2017-01-04 · Adaptive Traffic Control Systems...
Transcript of Freeway Adaptive system - Texas A&M University · 2017-01-04 · Adaptive Traffic Control Systems...
SH 242ADAPTIVE TRAFFIC SIGNAL
SYSTEM DEPLOYMENT
TxDOT Houston
October 13, 2015
Steve Chiu – TxDOT
Manu Isaac – Kimley-Horn
The Corridor
SH 242
– North of Houston
– Near Woodlands
Six Signals west of IH 45 (St Luke’s to Gosling)
In a Rapidly Growing Area
Congested with Closely Spaced Signals
Unpredictable Traffic Patterns
–Serves a College, Schools, Churches, Shopping Centers, Hospitals, etc.
2
Adaptive Traffic Control Systems (ATCS)
Automates Signal Monitoring and Timing Adjustments
Adjusts Timings in Real Time Based on Traffic
ATCS is Gradually Gaining Acceptance in US
Few Adaptive Systems Available
– SCOOTS, SCATS, RHODES, OPAC, InSync, ACS Lite, etc.
ACS Lite was used for SH 242
3
Why ACS Lite?
Developed by FHWA
Focus on Reducing Installation and Operations Costs
Collaborative Effort initiated in 2002
– Siemens, University of Arizona, Purdue University, and few
Controller Manufacturers
Four Field Evaluations in 2007
– Included Houston, TX (others in OH, FL, CA)
Houston’s ACS Lite was Deactivated shortly
– TxDOT still retained License
In 2012 - TxDOT Houston Decides to Use it for SH 242
4
ACS Lite Overview
Primarily for Closed Loop Arterial Signal Systems
Designed to Adapt the Splits and Offsets
Maximum of 32 signals in a System
Minimal Firmware Upgrades
Adaptive Computations Isolated to a Single Controller
Cycle Lengths based on Time of Day (TOD) schedules
Specified Optimization Steps (5-10 minutes)
Adjusts Splits and Offsets
by small amounts (2-5 seconds)
Significant Benefit with Minimum Agency Investment
5
SH 242 Signals
1 Diamond and 6 Standard intersections
6 signals using ACS Lite – but not IH 45 Diamond
– St Luke’s, Maverick, Achievement, Honor Roll, Windsor Hills, Gosling
Majority have Split Side Street Phasing
Had Video Detection but not very Functional
Fiber Communication between Signals
NEMA cabinets with mainly Siemens Controllers
6
Signal Equipment Requirements
Communications - IP or Serial
Vehicular Detection
– Can be any Detection Technology
– One Detector for each Phase
– Individual Lane-by-Lane Monitoring Preferable
– Stop Bar Detector (within 100 ft of Stop Bar)
– Advance Detection in “Dilemma Zone” (optional)
– Use Exit or Mid-block Detectors for Saturated Corridors
– Individual Detector Lead-In Cables and Cards
7
Pre-Deployment Tasks
Field Investigation
Traffic Data Collection
– 24-hour ATR Counts
– Turning Movement Counts
– Travel Time Runs
Signal Timing Development
– Baseline to run ACS Lite System
Communications and Detection
8
ACS Lite Implementation
ACS Lite Software
Adaptive Master
Signal Upgrades
– Controller Switch-outs
– Detector Installation
– Detector Cards
Comm. Setup
IP Addressing
9
ACS Lite Programming
ACS Lite has a User Friendly GUI
Similar to Many Signal System Software
System Modules
Configuration
– Detector
10
Programming – Date/Time/Schedule
Date/Time Module
Schedule/TOD Plans
11
Programming – Ring/Phase
Ring Configuration
12
Phase Data
Programming – Patterns
Patterns or Split Plans
Multiple Patterns for Each Split
Number of Patterns per Split is User Defined
13
Programming – Adaptive Setup
ACS Lite Adaptive Settings
– Global Settings
– Controller-Specific
14
Programming – Adaptive Setup
Global Settings
– Offset
– Split
– Adjustment Interval
Controller Specific
– Phase Biasing
– Peds, Transitions
15
ACS Lite Operation
Check all setups are validated
Turn System to Control Mode
Watch it Run
System Monitoring
–Phase
–Offset
–Detector
–Historical Data
16
ACS Lite Status Monitoring
Phase Utilization
– Saturation Rates
– Average Green
– Unused Green
Detector Status
17
ACS Lite Status Monitoring
Flow Profile
– Offset Adjustment for Progression
18
ACS Lite Split Adjustment
Splits Adjusted Based on Utilization
– Split Status is Color Coded
19
Summary
Travel Time and Delay Savings
– Travel times: ~10%; Delays: ~25%
Post-Deployment Intangibles
– Less Congestion
– Fewer Complaint Calls
–Minimized Queues
Next Steps
– Add Adjacent Signals including Diamond
– Other Controllers and Corridors
20
Thank you
Manu Isaac, P.E. Steve Chiu, EIT
Kimley-Horn and Associates Texas Department of Transportation
Houston, Texas Houston District
281-920-6306 713-802-5936
[email protected] [email protected]
21