| description abstract | Vehicles in homogeneous traffic follow lane-based movement and can be conveniently modeled using car-following and lane-changing models. The former deals with longitudinal movement behavior, while the latter deals with lateral movement behavior. However, typical heterogeneous traffic is characterized by the presence of multiple vehicle types and non-lane-based movement. Because of the off-centered positions of the vehicles, the following driver is not necessarily influenced by a single leader. Additionally, the following behavior of the subject vehicle depends on the type of the front vehicle. Unlike discrete lane changes in the case of lane-based traffic, heterogeneous traffic streams require modeling of continuous lateral movements. Hence, the existing driver behavioral models may not be able to represent the heterogeneous traffic behavior accurately enough. To address these critical issues of heterogeneous traffic, a space discretization–based simulation framework is proposed. The lane is divided into strips and the vehicles are assumed to move along the strips. A vehicle may occupy a multiple number of strips governed by its width. A model for longitudinal movement is proposed to take account for the multiple leader and vehicle-type dependent following behavior. The lateral movement model allows tactical overtaking maneuvers by a vehicle (in anticipation of better traffic conditions), which may require multiple strip changes. Thus, continuous lateral movement can be modeled by defining very small strip widths. On the other hand, the proposed simulation framework retains the concept of lane-based movement when the strip width equals the lane width and can be used even for the traditional lane-based traffic streams. The same concept was extended to model the vehicular movements at and within the intersection. The proposed framework, termed | |
