Green Time Extension Method of Transit Signal Priority Control for Phase Overlapping Intersection

Aiming at the transit priority control problem under the existence of phase overlapping constraints at signalized intersection, this paper proposes a green time extension method based on non-linear programming. On the basis of the traditional ring-barrier, an improved phase signal timing structure is proposed to address the issue of overlapping. Further, a non-linear programming model for green time extension is presented, in which the objective function aims to optimize the transit priority effect while minimize the adjustments required for non-transit phases, and the constrains include minimum green time, maximum green time, overlapping rules and migration of coordinated phase. The numerical analysis results indicate that under the constraint of a fixed overlapping duration of 4 seconds and the existence of phase coordination, the proposed method can extend the green time for transit priority phases by 166.7% more than the traditional timing scheme. Moreover, the standard deviation of green time adjustments for non-transit phases is reduced by 43.1% compared to the traditional timing scheme under the same extension effect.