Abstract
One of the measures to inhibit conflicts between pedestrian and left-turning vehicle at crosswalk of signalized intersections is, to provide separate phases for pedestrian and turning vehicle, such as exclusive pedestrian phase or Leading Pedestrian Interval (LPI). LPI is the phase which pedestrian green is displayed a few seconds ahead of vehicle green phase, and in this preceding time interval, a part of pedestrians can be protected from the conflicting left-turning vehicles. From the viewpoint of safety and mobility performance, LPI can be positioned between the conventional four-phase type in which the concurrent pedestrians and vehicles share the same signal phase and the exclusive pedestrian phase type. However, the safety and mobility performance of these three types of signal phasing is unclear. Thus, this study investigates and compares delays of pedestrian and vehicle, degree of saturation, capacity and pedestrian exposure time under those three types of signal phase types. Then an application range of LPI and the boundary condition of exclusive pedestrian phase are discussed.
