Use of HITL in Bus Priority Design Kevin Balke, Ph.D., P.E. TransLink ® Research Center Director Texas Transportation Institute Hardware-in-the-Loop Symposium Portland, Oregon July 29, 2003

Presentation Outline Algorithm Development and Testing Product Evaluation Sensor Location Design

Algorithm Development Proof-of-concept testing of algorithm Investigated New computer algorithm Manipulating traffic signal parameters in real traffic signal controller Evaluate whether algorithm performs as designed

Product Evaluation Test functionality of controllers/ technology Compare features in similar situations Develop deep understanding of how a product responds Controlled environment

Sensor Location Design Recent application of HITL technologies Conducted as part of Houston METRO’s installation of Regional Traffic Computer Signal System (RTCSS) Investigate question  where to place optical detection zones?

Houston Metro TSP Architecture Naztec 2070 w/ NextPhase ® Software 3M Opticom® Series 700 System Priority Phase Call Receiver Phase Selector Emitter

Houston Metro Issues Near-side bus stops ≈ 75% are nearside stops Many priority systems designed for far side stops Emitter Range > 2500 ft in ideal conditions Designed for emergency vehicle preemption How do you apply to transit priority?

Our Study What is the optimal length of the detection zones? Too far  “priority” occurs before bus gets to intersection Too close  “priority” hasn’t started when bus arrives Investigate interaction between: Bus stop location Detection zone location Priority algorithm performance

Our Approach Use HITL Simulation VISSIM model of two intersection Naztec controller with planned NextPhase timings Three bus stop locations 1500 ft upstream of intersection 50 ft upstream of intersection Two bus stops on same approach  100 ft and 500 ft

Detection Zones Lengths Varied detection zone length 1500 ft, 1000 ft, 500 ft, 100 ft, and No detection x Detection Zone Length

MOEs Probability of bus “successfully” clearing intersection without stopping Bus Delay

Lessons Learned Optimum detection range between 1000 ft and 1500 ft Exact length will vary depending upon Cycle length Degree of congestion Passenger demands (dwell times) Type of TSP logic Do not include multiple bus stops or intersections

Questions