Every urban area experiences traffic congestion to some extent. When congestion becomes extensive and repetitive, measures to increase the capacity or to reduce the demand should be implemented. This must be accomplished in a time of rising travel demands, rising costs of construction, depleting fiscal resources, and increasing concern for safety and the environment. It is within this framework of circumstances that the managers of urban freeways are considering increasing vehicular capacity within the limits of the existing freeway right-of-way by narrowing lanes and utilizing the shoulders as additional travel lanes. The reduction in design standards and the partial or complete elimination of freeway shoulders are departures from the original freeway design concept. Howerver, the enormous amounts of time and fuel that are wasted during each peak period of the day must be reduced.