DYNAMIC STABILITY, TRAFFIC EQUILIBRIUM AND THE LAW OF PEAK-HOUR EXPRESSWAY CONGESTION

Anthony Downs's (1962) traffic congestion analysis is given a generali zed theoretical foundation. It is demonstrated that only two equilibri um saddle points-one stable, the other unstable-can be attained. Once the stable equilibrium is reached, traffic planning and control measur es such as drastically increased metering and/or a metropolitan rail t ransit alternative must be in place so as to maintain equilibrium. If not, the expressway system eventually reaches gridlock. It is also sho wn that the analyses of Thomson (1977) and Mogridge (1986) parallel Do wns's analysis and lead to the same conclusion.