Effectiveness of Bus Priority Lane as Countermeasure for Congestion

The main objective of this research is to identify the effectiveness of the bus priority lane in Shizuoka City, Japan, as a countermeasure for traffic congestion. Shizuoka City, the capital of Shizuoka Prefecture in Japan, suffers from frequent traffic congestion. To tackle this problem, authorities of Shizuoka City tested a pilot project that implemented bus rapid transit (BRT) strategies. This project included a bus priority lane along a 3-km segment and a bus priority signal system. The project data were obtained mainly through traffic surveys, bus surveys, and questionnaire surveys, which were conducted by the authors and by Shizuoka City authorities. All these surveys were carried out twice, before and after the implementation of BRT strategies. After priority treatments were introduced, the number of vehicles using the main road was reduced. Also, queue-length and jam-length measurements showed signs of easing of traffic congestion, and travel times of general vehicles were improved. Although the change associated with total travel time of buses was not statistically significant, it still showed a reducing trend. However, travel times of buses, excluding dwelling times, showed a significant reduction. The difference of significance associated with the above travel parameters was mainly caused by the increase incurred in dwelling times of buses. It was evident that the smoothness of traffic flow along the bus lane as well as along the general traffic lane was improved by the BRT project.