Publication Detail

Making HOT lanes benefit every traveler --- design, pricing, and analysis


Research Report

Suggested Citation:
Zhang, Michael, Gao Hang, Maged Dessouky, Wei Gu (2022) Making HOT lanes benefit every traveler --- design, pricing, and analysis. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-22-104

High-occupancy toll (HOT) lanes, as high-occupancy vehicle (HOV) lanes that permit solo-drivers to use them with a charge, play an important role in reducing congestion, vehicle hours traveled (VHT), and vehicle miles traveled (VMT) in the morning commute. In this project, we formulate the morning commute problems with mixed traffic flows on HOT lanes as Differential Complementary Systems (DCS) under two scenarios: (1) two-equilibria model: with total number of solo-drivers and carpoolers fixed, carpoolers reach one equilibrium while solo-drivers reach another (at an equilibrium state, the travel costs of individual commuters are identical); (2) one-equilibrium model: with total number of travelers known, carpoolers and solo-drivers reach one equilibrium. Unlike previous research, our models can jointly determine the departure time choice, lane choice, and/or mode choice. The proposed continuous-time models are converted into discrete-time subproblems. Analytical models are then developed to quantify the time-variant inconvenience costs under equilibrium conditions and set the dynamic toll charges on HOT lanes to avoid queueing. Based on the data from the Caltrans Performance Measurement System (PeMS), the DCS models and analytical models are validated in case studies. Results show that our proposed models can benefit both carpoolers and solodrivers on HOT lanes: (1) our dynamic tolling approach can avoid congestion on HOT lanes; (2) our model outperforms a modeling approach without tolling; (3) if the HOT lane is underutilized by carpoolers, more solo-drivers would pay to use them; (4) commuters prefer to use carpool when there are more HOT lanes; (5) the overall travel cost, delay, VHT, and VMT per commuter are decreased when more general purpose (GP) lanes are converted into HOT lanes.

Key words: Carpooling, High-occupancy toll lane, Morning commute, Congestion-free