Dynamic Pricing Algorithm with Embedded Controller for High Occupancy Toll Lanes

Today more and more Intelligent Transportation System (ITS) strategies are introduced nationwide to reduce congestion and maintain desired service levels on freeways. High Occupancy Toll (HOT) lanes (form of managed lanes) is one such ITS strategy. HOT lanes are intended to maintain certain level of service such as average speed, throughput, etc. One of the major challenges in achieving these objectives is the time delay (due to long stretches of HOT lanes) and the resulting uncertainty in the throughput calculated at the end of the HOT lanes. HOT lanes need to have pricing algorithms that control the traffic by considering this time delay between the checking point and the tollbooth. This paper introduces a PID controller based pricing algorithm that addresses this need. A simulation model of I-95 is used to demonstrate the effectiveness of this approach.