The average amount of daily driving per person decreased between 2005 and 2011 according to a new analysis by the Transportation Planning Board.

During that time range, the metropolitan Washington region's population increased by nearly 350,000 people to around 5.1 million -- an increase of 7.3%. Over that same six-year period, total daily driving stayed about the same—around 110 million vehicle miles a day. This resulted in a 6.1% decrease of driving per person from 22.9 miles a day in 2005 to 21.5 miles a day in 2011, reversing a decades-long trend of ever-increasing driving.

The analysis showed the trend of less driving per person occurred in all parts of the region. The biggest declines occurred in the region’s outer suburbs of Charles, Frederick, Loudoun, and Prince William counties.

Staff noted several possible causes for the decline, including the recession, fuel prices, more widespread use of e-commerce and electronic communications, telecommuting, as well as shifting preferences toward less travel by car, especially among young people. The analysis also showed the decline in driving per person began before the recession started.

A similar trend of less driving per person has been occurring nationally as well. The annual amount of driving per person has decreased 6.7 percent between 2004 and 2012.

The analysis was part of an effort to update the TPB’s computer models, which predict future travel patterns and inform transportation planning decisions. Reducing vehicle miles traveled per person is also a target in COG’s Region Forward vision for metropolitan Washington.