Source: Texas Transportation Institute. The Urban Mobility Study. http://mobility.tamu.edu/Average Number of Hours of Delay per Peak Commuter per Year, Selected
American Cities, 1982-2003Between 1980 and 1999, route miles of highways increased 1.5% while
vehicle miles of travel grew by 76%. Due to congestion, most large American
cities have experienced increasing delays since the 1980s. Traffic delays
are commonly measured by comparing the actual/observed travel time (dominantly
during commuting) with the theoretical travel time which is the amount
of time it would take if there were no delays. The difference equals
to the amount of time lost because of traffic delays. On average, commuters
in the United States lost 47 hours in 2003 due to congestion, the equivalent
of 5.8 work days.
