Abstract:

In heterogeneous traffic conditions, the designs of signal timings were based on motor traffic flows in most traditional signal control methods, which may reduce the motor vehicles′ operating efficiencies and hinder the traffic engineers from finding the optimal signal timings. Therefore, a traffic signal actuated control method for heterogeneous traffic was proposed, which targets on motor and non?motorized vehicle traffic flows at isolated intersections. This method combined an optimization algorithm and an actuated control logic. The basic green time of each phase was optimized according to the real?time data obtained from the heat?imaging traffic detectors. Then, the initial green time and the maximum green time of each phase, the key parameters of the actuated control, were formulated as the expansions of the basic green time. The method was evaluated using field data, and the rationality analysis shows that the non?motorized vehicles in heterogeneous traffic have an influence on the traffic flows. In addition, an offline verification was designed, and the results show that the average vehicle delay is reduced by 7.69% when considering the non?motor vehicles in the optimization algorithm, while the proportion of oversaturated cycles is decreased by 80.77% under the actuated control.

Key words: engineering of communication and transportation system, heterogeneous traffic, traffic signal actuated control, isolated intersection, traffic intensity, occupancy time