Bus Signal Priority Strategies for Multi-directional Bus Routes

摘要

Though the Bus Signal Priority (BSP) system is well known as an effective way to enhance the service quality of bus travel, the effectiveness of the BSP system significantly depends on the traffic and network conditions. Particularly, most previous use of the BSP system were applied as a corridor-based strategy targeting a few bus lines moving on a corridor; hence existing BSP systems cannot guarantee the service quality of all of the buses in a complex and congested network conflicted by numerous bus lines. Therefore, an appropriate signal priority strategy should be identified before the introduction of a BSP system according to the network conditions. As an alternative to the corridor-based signal priority strategy, this study proposes a Multi-directional Bus Signal Priority (MBSP) approach and analyzes the effectiveness of different priority strategies given various network conditions using the simulation tool Paramics. In addition, to manage conflicting and competing requests, a priority-based rule is proposed and compared with the First-In-First-Service (FIFS) rule. The simulation results showed that a corridor-based BSP was effective for a concentrated bus network, whereas it might deteriorate other traffic flows with little improvement of the bus service for a diverse bus network. For a diverse bus network, other strategies apart from the priority-based MBSP strategy cannot be expected to improve the reliability of bus service.