Timing Equilibria in an Urban Model with Congestion

All spatial urban models with congestion assume that the departure (arrival) time of commutes is exogenously determined and assume that travel speed at a given time and location depends upon the traffic density at that point in time and space. This paper presents a framework that encompasses such models, but allows workers to choose the time at which they leave home (arrive at work). This paper then proves that in general only one equilibrium exists for urban models with traditional congestion technology: a commuting pattern in which commuting is continuous and the rush hour never ends, which is unrepresentative of traffic patterns anywhere. This paper concludes by discussing alternative general equilibrium urban models with congestion that may have more realistic equilibria.