This paper presents a dynamic version of the standard static economic model of road traffic congestion, based on car-following theory. It is proven formally and illustrated numerically that the "hypercongested" equilibria found in the standard model are dynamically unstable. For arrival rates of users below the road's maximum capacity, the model reproduces the non-hypercongested stationary state outcomes found in the standard model. When the arrival rate exceeds this maximum capacity, however, the model produces outcomes consistent with Vickrey's model of bottleneck congestion. The model thus offers an integration and a generalization of these two archetype models. © 2001 Academic Press.