Token system balances fairness and speed in traffic lanes
Token Economy Design for Fair and Efficient Highway Congestion Management with Express Lanes
Computer Science and Game Theory
Summary
Traffic congestion on highways can be unfair when faster lanes are only open to certain drivers. The authors studied a way to use tokens instead of money to decide who gets to use the faster express lane. Drivers earn and spend tokens to take turns using the lane, which helps keep traffic moving smoothly while being fairer. Their tests with real traffic data showed that this token system keeps travel times low and reduces the feeling of urgency for most drivers.
What this means in practice
- •For transportation planners: Design token-based lane allocation policies to improve fairness without increasing traffic delays on congested highways.
- •For traffic management teams: Implement token systems in traffic control to balance lane usage dynamically and reduce perceived travel time among drivers.
Authors
Leonardo Pedroso, Juan Pablo Bertucci, W. P. M. H. Heemels, Mauro Salazar
Abstract
We study the design of a token economy for highway lane allocation that aims to improve fairness without sacrificing traffic efficiency. Motivated by the San Mateo 101 Express Lanes Project, we consider a setting in which high-occupancy vehicles have unrestricted access to an express lane, while the remaining users can alternate between regular and express lanes by earning and spending nonmonetary tokens. We model the resulting interaction as a finite-population dynamic congestion game with heterogeneous time preferences and limited-information evolutionary policy revisions. Building on a mean-field approximation, we derive token prices that enforce the system-optimal lane split while inducing fairness over time through turn-taking. The scheme is evaluated in a microscopic traffic simulation with real-world demand data. The results show that the proposed prices yield nearly the same average travel time as a baseline scenario in which no lane is reserved as an express lane, while substantially reducing urgency-weighted perceived travel time. These findings highlight token economies as a promising alternative to monetary congestion pricing for fairer management of scarce road capacity.