What is defined as the time difference between successive vehicles as they pass a given point?

The term that describes the time difference between successive vehicles as they pass a given point is headway. Headway is an essential concept in traffic flow analysis, as it provides insights into the spacing and behavior of vehicles on a roadway. It is typically measured in seconds and reflects the interval between one vehicle leaving a point and the next vehicle arriving at the same point.

In the context of traffic management and transportation engineering, understanding headway is crucial for optimizing traffic signal timing, roadway design, and safety measures. Smaller headways generally indicate higher traffic density and flow, while larger headways can suggest lighter traffic conditions.

Density, flow rate, and spacing relate to different aspects of traffic behavior, but they do not specifically capture the time interval between vehicles. Density refers to the number of vehicles per unit length of the roadway, flow rate measures the number of vehicles passing a point over time, and spacing is related to the physical distance between vehicles, not the time gap. Therefore, headway is the most accurate term for the scenario described.