Average Weekday Vehicle Trips and Vehicle Miles Reduced By ACCS

ACCS impact on the number of vehicle trips and trip miles that were diverted to other modes has increased significantly over the past five years


Photo: Bicyclist and busVehicle trips are the total number of unique trips made by a single private vehicle, such as an automobile, van, pickup truck, or motorcycle. Vehicle miles traveled is a unit to measure the distance of vehicle travel made by these vehicles. Each mile traveled is counted as one vehicle mile regardless of the number of persons in the vehicle.5 This measure is the number of average weekday vehicle trips and vehicle miles traveled that were reduced in Arlington through the programs and activities of Arlington County Commuter Services (ACCS).6

Why is This Measure Important?

Reducing the number of vehicle trips and vehicle miles traveled on an average weekday in Arlington County limits harmful air pollution, traffic congestion, and roadway related costs.

Current Status7

Since this data was first tracked in 2008, the number of vehicle trips reduced on an average weekday has risen from 38,000 to over 41,000 (an 8 percent increase), corresponding with a 34 percent reduction in the number of vehicle miles traveled.

Considering that the average lane of interstate highway carries approximately 8,000 – 12,000 vehicles in both rush periods, a reduction in trips by 41,000 is a significant benefit produced by ACCS.

Between 2001 and 2009 the number of daily vehicles miles traveled on Wilson Boulevard in Clarendon fell by 23 percent, while Glebe Road in Ballston experienced a daily vehicles mile traveled reduction of 31 percent.

41,128 Number of vehicle trips ACCS programs helped eliminate in FY2013


5Definition adapted from the Bureau of Transportation Statistics Dictionary.
6The methodology used to derive these calculations is detailed in the 2008 "Making an Impact" Report, available online at: http://mobilitylab.org/2008/08/15/accs-making-an-impact-fy2008/.
7ACCS Making an Impact Reports, 2008-2011, available online at http://mobilitylab.org/tag/making-an-impact/, as of October 2012.