Analyzing Traffic Performance of Toll Plazas Using Performance Box: A Case Study

The objective of the present study is to analyze the traffic characteristics at Ghoti Toll Plaza (GTP) under mixed traffic conditions using a performance-box (P-box), a Global Positioning System (GPS)-based instrument. P-box records the actual time taken by a vehicle to cross the toll plaza, its acceleration and deceleration values, zone of influence (ZOI) of the toll plaza, system delay, vehicle’s cruising speed before approaching the toll plaza, number of the vehicles in the queue and control delay. Results show that the ZOI starts at 250 m upstream and downstream of the tollbooth. The control delay was measured between the instances when a vehicle starts to decelerate after joining the queue and regains its original speed after negotiating the tollbooth, the vehicle starts to accelerate. In comparison, the system delay includes the time elapsed between the moments when the vehicle joins the queue and leaves the tollbooth. The minimum and maximum control delays were found to be 15.01 s and 246.30 s, respectively. A linear relationship was established between the number of vehicles in the queue and the control delay. The delay ratio (the ratio of control delay to system delay) varies from 1.07 to 2.10.  A negatively correlated linear relationship found between the number of vehicles in the queue and delay ratio. Control delay to system delay conversion factor is found to be 1.31 for the toll plazas. The outcome of the present study will help practitioners estimate the control delay that could be used to derive users’ ideal waiting time cost and in the planning and designing of toll-plaza.