Modeling Vehicle Interactions and the Movement of Groups of Vehicles

Chapter 1 discussed the movement of an individual vehicle and provided the equations of motion assuming there are no other vehicles around. This chapter examines the interactions between vehicles, which is at the heart of traffic flow theory. It is these interactions that produce the observed traffic operational conditions, including crashes and congestion. Traffic operational characteristics of interest include capacity (i.e., the maximum amount of traffic that can pass through a point or section in vehicles or other units of traffic per unit time), prevailing speed (i.e., the speed at which the facility operates under a given set of prevailing conditions, including the demand, the highway design, etc.), delay, and travel time. These characteristics are discussed in more detail in Part II.