Washington area drivers are encountering less traffic and spending less time stuck in it, according to a recent Transportation Planning Board study that found significant declines in travel delay on area roads between 2010 and 2012.
The study found that peak hour delays experienced by road users on a typical weekday fell markedly from 2010 to 2012.
In 2010, it took drivers 21% longer, on average, to reach their destinations during the morning and evening commutes than it otherwise would in free-flow, or traffic-free, conditions. By 2012, that number had fallen to 13% during the morning commute and to 14% during the evening commute during both time periods.
The TPB quantified these peak hour delays using GPS-based speed information gathered by a private company, INRIX, from travelers who have agreed to share the information anonymously from their smartphones or in-vehicle navigation devices, along with other publicly available data sources.
The Maryland Department of Transportation asked the TPB to carry out this particular study to determine whether traffic on local roads in the vicinity of the Intercounty Connector -- a major new east-west route connecting I-270 in Montgomery County to I-95 in Prince George's County -- had improved since the highway opened in 2011.
The TPB study found that travel conditions on local roads around the ICC saw greater improvements in travel conditions than the region as a whole.
Before the ICC opened in 2010, trips on roads in the surrounding area at peak hours took 43% to 45% longer than in free-flow conditions. By 2012, that number had fallen to around 30%.
Increases in roadway capacity, like the ICC, surely contribute to such improvements, especially given that total daily driving on area roadways saw no change between 2005 and 2011, holding more or less steady at about 110 million vehicle-miles a day.
Weak economic conditions, like those that have plagued the national economy since 2007, have played a role in keeping demand on the region's roadways steady even as population has increased. Heightened sensitivity to fuel price volatility, more widespread use of e-commerce and electronic communications, increased telecommuting, and shifting preferences toward less vehicle travel have also probably played a role.
As long as the region maintains steady levels of vehicle travel, road improvements like the ICC and other transportation enhancements should result in further improvements in travel conditions.
Whether or not the downward trend in travel delay observed over the last two years will continue is unclear. As it has for many years, the TPB will continue to monitor traffic conditions throughout the region to try to understand whether the observed declines are temporary, or represent a longer-term change in regional travel conditions.