Continuum modeling of park-and-ride services in a linear monocentric city with deterministic mode choice

The objective of this paper is to enhance the insights into commuters' travel choice behaviors in a competitive railway/highway system with continuum park-and-ride services along a travel corridor. It is assumed that parking charges gradually decrease from the city center to the corridor boundary and commuters are continuously distributed along the corridor. Commuters choose either the railway or highway for traveling from their home to the center in the morning. If choosing the highway, the commuters also consider the use of park-and-ride facilities available anywhere throughout the corridor. Given these assumptions, we propose a deterministic continuum equilibrium model to characterize commuters' modal choices and park-and-ride transfer behaviors. We prove that, at equilibrium, the variable travel cost per unit distance on the highway is not higher than that on the railway along the corridor. As a result, the railway is used only between the city center (the destinations of morning commuters) and some location in the linear city, beyond which all commuters choose the highway. Furthermore, commuters living closer to the city center choose the park-and-ride facilities that are simultaneously chosen by those who live farther away from the city center. The model is solved numerically through its transformation into a discrete version using a supernetwork approach and demonstrated with numerical examples together with a discussion of the effect of park-and-ride services and pricing on travel behaviors.