What is the definition of traffic flow?

The definition of traffic flow primarily refers to the movement of a group of vehicles on a road. This encompasses how vehicles interact with each other, their spacing, speed, and overall dynamics as they travel along roadways. Understanding traffic flow is critical for analyzing traffic patterns, improving road safety, and implementing effective traffic management strategies.

While the other options touch on related aspects of transportation, they do not fully capture the essence of traffic flow. For instance, speed limits pertain to regulations governing vehicle speeds rather than the broader interaction of multiple vehicles. Coordination of pedestrian and vehicle activity focuses on the interface between different modes of transport, which is a separate consideration from just vehicles moving together. Similarly, vehicle behavior in parking lots involves stationary or low-speed conditions that differ significantly from the concept of traffic flow on active roadways.