What Influences Traffic Congestion?
Road use, as measured by vehicle miles traveled (VMT), has increased significantly over the past few decades as a growing population and rising incomes have led to increased car ownership, growth in low-density housing in suburbs and “ex-urbs,” new roads and a long-term trend toward lower real costs of personal transportation. In the last two decades, the rate of increase in VMT has been much higher than the growth in overall road capacity. As a result, a higher number of road miles experience congestion and serious traffic jams, while some localities suffer from chronic congestion, especially during prime commuting hours. The costs of congestion have also risen — lost wages, eroded productivity and the increased cost of freight transport. In Virginia, congestion problems are most serious in the Northern region close to Washington, DC and in the Hampton Roads region, where traffic is forced into bottlenecks at bridges and tunnels. A combination of factors contributes to congestion, in
