Congestion Pricing and Motor Vehicle Emissions: An Initial Review
Traffic congestion is now widespread on freeways and arterials in most urban areas. The Federal Highway Administration estimates that more than 65 percent of urban freeways are congested during peak periods, creating more than 2 billion vehicle-hr of delay and user costs in excess of $15.9 billion per year (GAO 1991). Congestion levels are also rising, meaning that the delay, energy, and air quality impacts of congestion continue to worsen. Because there has recently been increased regulatory focus on implementing economic incentives in the environmental arena (EPA 1992a; Guensler 1992; Ketcham 1991; Regulatory Flexibility Group 1991; South Coast Air Quality Management District 1991; Hahn and Stavins 1990), it is natural that congestion pricing would be explored as a means to achieve transportation behavioral changes in the urban areas with the worst air quality.