Samenvatting
The hydrodynamic theory of traffic flow along long crowded highways is based on the concept of the flow of a hypothetical "traffic fluid" that satisfies an equation of continuity and an "equation of state". This paper considers the derivation of several "equations of state" by a simple method. The derived equations of state appear to explain certain experimental observations. The wave propagation of traffic disturbances in cases where the flow rate of traffic flow is a function of the density and the variation of the density with respect to space and time is also studied.