Traffic Rationing and Short-Term and Long-Term Equilibrium

Road rationing as a possible alternative or supplement to road pricing has been implemented in several large cities but has received limited attention in the theoretical transportation research community. This paper analyzes the effects of road rationing under short-term and long-term traffic equilibrium. Short-term equilibrium describes the situation under which no one changes car ownership but simply obeys the rationing rules. In contrast, long-term equilibrium under road rationing takes into account the public's self-adjustment activities such as car consumption and car disposal and characterizes the equilibrium situation in which no incentive exists to change car ownership. For short- and long-term rationing, equilibrium patterns are determined, and the average daily trip travel time with one car is found to be the essential factor in determining the attainability of Pareto improvement. Under the same rationing degree, it is found that Pareto improvement is easier to obtain by short-term rationing than by long-term rationing. If Pareto improvement fails, the subgroups who benefit and suffer from rationing are discerned.