This report describes a cost-effective data collection system for Caltrans 170 traffic signal controller. The data collection system is based on TCP/IP communication over existing low-cost mobile communication networks and Motorola® iDEN1 mobile handsets. An adaptive wireless flow control protocol is developed to ensure reliable continuously communication over unstable wireless link. The system is fully integrated with Caltrans 170 signal controllers and its CTNet server program. Lab testing shows that with the adaptive flow control protocol, each handset can deliver data fetched from signal controllers at a period of 200ms continuously over 95% of the time. One set of data collection device costs less than $100 and its monthly cost can be as low as $10.

In support of efforts to improve traffic signal timing to accommodate the needs of bicyclists, observations have been made of the timing of bicyclists’ intersection crossing maneuvers. Video recordings were made of bicyclists’ crossings and the video images were processed to extract the bicyclists’ trajectories. These were synchronized with video images of the traffic signals so that the timing of the bicyclists’ maneuvers could be determined relative to the signal phase. The processed data have yielded cumulative distributions of the crossing speeds of bicyclists who did not have to stop at the intersection and the start-up times and final crossing speeds of the bicyclists who had to cross from a standing start. A unique feature of these data is the timing information relative to the traffic signal, which will be essential for determining signal phase durations. The sensitivity of the bicycling performance measures to differences between the data collection sites indicates the desirability of collecting such data under a wider range of conditions.

This document reports the continuous efforts conducted by California PATH Program on the development and implementation of an Adaptive Transit Signal Priority (ATSP) system. The ATSP system has three distinguished features, including: (1) providing priority to transit vehicles while making a tradeoff between bus delay savings and the impacts on the rest of the traffic, (2) utilizing existing AVL/communication system already instrumented on buses to continuously monitor bus locations and predict bus arrival times to intersections and to request signal priority, and (3) building upon closed-loop signal control systems with 170E controllers. These features allow ATSP to have potential for wide-scale implementation. This report describes the development of ATSP algorithms, the field testing results of the prototype ATSP system and the feasibility analysis for utilizing existing transit communication for ATSP.

This document reports the results of the evaluation of the Transit Signal Priority currently under operation at AC Transit. The paper discusses about the Measure of Effectiveness and a quantitative evaluation method for TSP. It reports the data collected and analysis conducted of the concerned TSP system and presented the evaluation results.