A model for queuing toll policies incorporating cost-sharing characteristics of carpooling in the transportation network with capacity constraints

This paper introduces capacity constraints into a multi-modal transportation network, including solo driving, carpooling, and public transit, and proposes two queuing toll policies based on the cost-sharing characteristics of carpooling to eliminate physical queues. By incorporating traveler heterogeneity in the value of time, a multi-class user equilibrium model is developed to assess the impacts of capacity constraints and queuing toll policies on traffic equilibrium under three cases: 1) case 1, no tolls are charged to any travelers. Physical queues may occur on the saturated links; 2) case 2, the queuing tolls are charged exclusively to solo drivers, and it takes into account the scenario that the physical queues are not completely eliminated in the saturated link only with carpooling; 3) case 3, the queuing tolls are charged to solo drivers and carpooling travelers (i.e., carpooling drivers and riders). Then, an improved route swapping algorithm is proposed to solve the equilibrium model. Finally, numerical analysis based on the Winnipeg network is conducted to demonstrate the properties of the problem and the performance of the proposed model and algorithm. The results show that the proposed queuing toll policies can improve travel efficiency by encouraging carpooling and eliminating physical queues. Moreover, the differential impacts of the three cases on heterogeneous travelers’ mode choices and travel efficiency are explored. These findings provide a theoretical basis for the practical implementation of queuing toll policies.