Improving Operational Efficiency for a Two-Way Highway Toll Station

This paper addresses the over congestion issue at a real highway toll station and proposes the optimal design and operation policy to improve the overall system performance minimizing both customer waiting and toll station's operational costs. Based on the empirical data of Liuzhong Highway Tianshui Road toll station (LHTR-station), the real-time arrival rates of the traffic flows in both directions have been characterized via statistical analysis. Using an M/D/1 queuing model and stationary independent period-by-period (SIPP) and peak-hour approximations for the time-varying arrival rates, (i.e. two hours per period and 12 periods a day), we develop the optimal staffing levels in both directions of highway toll station. Then, the optimal staffing schedules are developed for different scenarios, for example, four-hour working a day, six-hour working a day, eight-hour working a day, and four-hour working and two-hour resting and four-hour working a day. The operating costs are compared for different schedules used in practice. Finally, using the empirical data of LHTR-station, we evaluate the performance improvement with the schedules suggested by our analysis. It has been found that the operation efficiency for LHTR-station can be improved significantly. This paper shows the value of using the operations research models innovatively to solve real-world problems.