A microscopic traffic simulation framework to evaluate the performance of bus priority lanes

Bus priority measures are widely considered effective at reducing traffic congestion and bus travel times. Traditionally, the performance of a bus priority measure is evaluated using traffic survey-based methods. However, traffic simulations can also be used as a decision support tool for transport planners to test different bus priority measures in a simulation environment and evaluate the measure’s performance before physical implementation. This research presents the development of a microscopic traffic simulation framework to simulate traffic flows when a bus priority lane (BPL) is in operation and compares its performance against the case where no BPL is in operation. A test-bed along the Galle Road corridor (in Colombo, Sri Lanka) from Cross Junction to Ratmalana was chosen to test the developed simulation framework. The performance of the BPL was evaluated by considering the changes in the vehicle speeds before and after implementing the BPL. Different demand configurations were simulated by varying the general traffic flow and bus flow to understand the BPL's feasible demand configuration(s). The simulation results showed that the BPL was feasible with a relatively high bus flow (240 buses per hour) and a relatively moderate general traffic flow (2,000 / 2,500 vehicles per hour).