The Cost of Congestion
Over time, slowing traffic exacts heavy costs on drivers. On average, congestion caused 47 hours of delay for U.S. commuters and commercial truck drivers in 85 urban areas during peak hours in 2003. For America's 13 largest cities, this number is much higher: 61 hours. Extra fuel is consumed on congested roads because of the effect that waiting in stop-andgo traffic has on fuel economy. In 2003, sitting in traffic wasted about 2.3 billion gallons of fuel, or almost 1.4 percent of all fuel consumed by lightduty and commercial vehicles that year.Waiting in traffic can also increase the cumulative amount of pollution emitted from a vehicle's tailpipe, which contributes to poor air quality and more greenhouse gas emissions.
Aggregating over the 85 most congested U.S. cities, the cost of time wasted in traffic and extra fuel consumed by commuters and commercial truck drivers due to congestion is estimated to have exceeded $63 billion in 2003. In Los Angeles, the city with the worst congestion, the fuel and time cost of waiting in traffic was calculated to be almost $1,600 per traveler in 2003. In Philadelphia, congestion is noticeably less than in Los Angeles, but the estimated cost to travelers is still high: $641 per traveler per year. In addition, businesses that rely on regular and on-time delivery of supplies have begun to maintain larger inventories to safeguard against unanticipated delays caused by congestion. A recent study conducted by the Department of Transportation confirms that congestion has resulted in higher transportation prices and less reliable pickup and delivery times for freight.