High Occupancy Toll (HOT) lanes have been proposed as one of the most applicable and cost-effective countermeasures against freeway congestion. By allowing Single Occupancy Vehicles (SOVs) to use High Occupancy Vehicle (HOV) lanes with a toll, excess capacities of HOV lanes can be utilized. Through balancing the pricing and vehicle occupancy constraints, an HOT lane system can optimize traffic allocations between HOT and General Purpose (GP) lanes and hence enhance the overall infrastructure efficiency. Since the HOT lane concept was initiated in 1993, HOT lane has been a hot discussion topic. HOT lane operations involve technical, political, environmental, and equity considerations and hence have fairly broad societal impacts.

Over the past 15 years, nine HOT lane facilities have been developed and put in use. With the field data collected from these HOT lane facilities, many important issues can be analyzed for better understanding the system. The NCHRP 03-96, Analysis of Managed Lanes on Freeway Facilities, research team collected a significant amount of field data from the identified HOT lane facilities in Florida, Washington, Minnesota, and California over the past two years. Based on these field data, several important issues, such as HOT lane capacity, impacts on HOV drivers, HOT lane users’ value of time, and optimal tolling strategies, were investigated by Dr. Wang and his NCHRP 03-96 research team. Major findings of their study will be reported in this talk.