Traffic flow variables

This lecture introduces traffic flow variables, including time-space diagrams, space-mean vs. time-mean definitions, and the relation between flow, density, and speed. It also covers methods of observing groups of vehicles and space-mean and time-mean speed calculations based on Edie (1963). Generalized definitions of flow and density are discussed, focusing on vehicle km traveled, vehicle hr traveled, and their relationships. The lecture concludes with a summary of traffic flow variables.