The Los Angeles DOT (LADOT) implemented a $10 million bus signal priority demonstration project along two corridors (Ventura Boulevard and the Santa Monica-Beverly Hills- Montebello route) in the City of Los Angeles, California. The initial deployment began in June 2000. The system consists of 331 loop detectors, 210 intersections equipped with automatic vehicle identification (AVI) sensors at the controller cabinet, and 150 transponder-equipped buses, and central control system software. Loop detection technology is used to detect the presence of a bus approaching the intersection. The bus identification is detected by the AVI sensor and sent to the transit management computer located at the LADOT transportation management center. The system checks the bus' schedule and headway to determine if it is early or on time. If the bus is behind schedule, one of four types of priority modes is granted. Loop detection was selected as the most reliable, accurate, and cost-effective detection technology, over radio-frequency antenna transponder detection and infrared beacon system. The cost per signalized intersection included an average of equipment (roadway and at intersection), and software costs.
Chada, Shireen and Robert Newland, Effectiveness of Bus Signal Priority: Final Report, Prepared for the Florida DOT and USDOT by the University of South Florida (CTR-416-04). January 2002.