Pub. date: 2008 | Online Pub. Date: May 28, 2008 | DOI: 10.4135/9781412963930 | Print ISBN: 9781412941655 | Online ISBN: 9781412963930| Publisher:SAGE Publications, Inc.About this encyclopedia
Heather M. Griffiths
The social problem called traffic congestion results when the number of vehicles using the existing transportation facilities and systems serving a country, city, community, or other area (infrastructure) exceed that infrastructure's carrying capacity. Characterizing traffic congestion are a decrease in the actual speed a vehicle may travel regardless of posted speed limit, increased travel time, and/or an increase in the amount of time it takes to enter an existing flow of traffic. The amount of traffic congestion depends on both recurring (regular rush hour traffic) and nonrecurring (congestion due to special road construction) variables. According to the U.S. Department of Transportation Federal Highway Administration (FHWA), since 1982 traffic congestion has increased in all cities across the United States. In 2003, the Texas Transportation Institute studied 85 U.S. urban areas and found that traffic congestion caused an estimated 1.9 billion hours of delay and cost an estimated $63 billion in wasted ...