October 13, 2015 SH 242 ADAPTIVE TRAFFIC SIGNAL SYSTEM DEPLOYMENT TxDOT Houston 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 Phase Data 12
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 Manu.Isaac@kimley-horn.com Steve.Chiu@txdot.gov 21