The Benefits of a Pilot Implementation of Public Transport Signal Priorities and Real-Time Passenger Information
This study evaluated a pilot project designed to provide real-time passenger information and signal priority to tram and bus lines in the City of Helsinki, Finland. Automated vehicle location (AVL) and computer assisted dispatch (CAD) systems were installed on Tram Line-4 and Bus Line-23. In addition, transit signal priority was provided on each route, and real-time schedule information was displayed at each transit stop.
Field measurements were collected from April 1998 to May 2000 in order to evaluate the technical performance of each system in terms of service accessibility, travel times, punctuality, and regularity. The evaluation was conducted using records of in-vehicle data, interviews, surveys, simulations, and a representative test ride observations before and after system deployment.
Delays, Travel Time, and Reliability
Delays at signals were reduced by 44 percent (1 min 13 sec) on the tramline, and 48 percent (3 min 18 sec) on the bus line. However, stop time for both modes increased slightly (3 to 5 sec) since drivers ahead of schedule increased their stop time to balance routing schedules.
Total travel times decreased 1 percent (21 sec) on the tramline, and 11 percent (3 min 18 sec) on the bus line. The reduction was primarily the result of reduced signal delays.
On-time arrival improved by 22 percent on the tramline, and 58 percent on the bus line.
Based on reductions in signal delay, travel time savings were estimated at 9 seconds per kilometer (sec/km). Since approximately 27 million passenger-miles per year accrued on the 8.1 km section of tramline; the system saved an estimated 67,500 passenger-hours per year. Correspondingly, the bus line saved 35, 800 passenger-hours per year.