It has been verified that the geometric design of the pre-signal system has immense effects on its efficiency. Take the length of the sorting area as an example; this design parameter is an important one that can affect the efficiency of the whole system. On the one hand, we would like to have PS-341 structure a sufficiently long sorting area to ensure that these transient queues do not spill back to the pre-signal [7]. On the other hand, the shorter the sorting area, the shorter the queue formed on each sorting lane and, therefore, the less the time taken to discharge
vehicles queued in the sorting area, meaning these vehicles do not need a long green time at the intersection, which is a scarce resource when the cycle length is fixed. At this time, we need to determine the optimal lengths of the sorting areas while making the above trade-offs. Numerical simulations confirmed that the capacity of a pre-signal system will drop sharply when the length of sorting area decreases under 100 meters [8, 11]. Meanwhile, the consistence of lane numbers between connected intersection arms will also affect the efficiency of pre-signal system. The pre-signal system should be carefully designed to minimize the detrimental effect on traffic progression. Existing researches adopted a series of optimization models to lower stops or delays [9]. Simulation based
optimization provides an excellent way to explore the temporal/spatial usage of road sources without extra costs [12]. With the geometric design of the pre-signal system according to the simulation based optimization, the queued vehicles in the sorting area can have
a better distribution for higher efficiency. One of the most important factors to make the optimized geometric design parameters credible is the calibration of driving behaviors in the sorting area of the pre-signal system [13]. Field observed driving behavior is suggested to be utilized in the calibration and validation process. The focus of this paper is to determine the optimal design of the pre-signal to obtain the best benefits of the traffic progression. The remainder of this paper is organized as follows. In Section 2, we address the major existing problems of the pre-signal system and then propose the methodology of this paper. In Section 3, we describe and model the driving Cilengitide behaviors at intersection’s sorting area. In Section 4, we improve the NaSch model to evaluate the influence of the design parameters of pre-signal system by adding a series of rules based on calibrated driving behaviors. In Section 5, we conduct an experiment using real field traffic data to evaluate the benefit of our proposed methodology. Finally, we end the paper by presenting conclusions and suggestions for future research in Section 6. 2. Methodology 2.1.