Maryland Avenue Safety Project: FAQ, part 3

studies & data 

Q: Has DDOT studied traffic patterns on and around Maryland Avenue? What about increased congestion and traffic diversion into the neighborhoods?

Yes. DDOT and its outside experts have studied traffic patterns on and along Maryland Avenue for years. As part of the City’s approval of the project in 2012, analysts recorded two weeks of traffic count data at various locations up and down the corridor. They then modeled present and future traffic flows using that traffic count data, population (transportation demand) growth and regional transportation data, and on-site qualitative analysis. In an expansive study for the Federal Highway Administration, DDOT looked at traffic volumes, potential delays, likelihood of traffic spilling over to other neighborhood roads, air pollution, and other potential impacts. The results of those analyses were reviewed by others within DDOT and the Federal Department of Transportation.  

Studies and analyses of traffic patterns decades into the future showed that traffic congestion is unlikely to increase in any significant way due to the Maryland Avenue Project. Delays at some traffic lights along Maryland Avenue might increase by a few seconds, but delays at other lights will decrease due, in part, to more consistent flow (e.g. fewer cars jumping back and forth between lanes) and better-timed lights.  

Those studies and analyses also showed that diversion onto neighborhood streets is not expected to be a significant issue. Drivers of approximately 50 cars during morning rush hours (fewer cars during the PM rush hour) are expected to divert to other routes as a result of the project. Two-thirds of those rush hour cars will take completely different routes – either to the north, along New York Avenue, Florida Avenue and similar routes, or to the south, across the Anacostia on Pennsylvania Avenue or 11th Street. The remaining one-third (approximately 16 cars) are expected to move to C Street, Massachusetts Avenue, and other east-west streets in that area.

A quick walk or drive around the neighborhood confirms DDOT’s quantitative analysis: the local alternatives to Maryland Avenue are not suited fast-moving through-traffic. Each of the lettered streets from D through G has stop signs and/or stop lights at the cross streets, and traffic on those cross streets forces cars to actually stop at the stop signs. DDOT has installed speed bumps, narrowed some streets, and made some blocks of those lettered streets one-way to further limit bypass traffic passing through the neighborhood. Finally, it is worth remembering that because Maryland Avenue is angled, it is the shortest route (i.e. the hypotenuse), so a driver diverting to one of the lettered streets would need to take a longer route along the (slow moving) legs of the triangle to wind up back at the same place. To the degree that cars divert away from Maryland Avenue, it is more likely that they will find a new route altogether when construction starts and then stick with that alternate route.

Q: Have traffic volumes increased since the City approved the Maryland Avenue Safety Project in 2012?  

No. DDOT conducts studies every year of the number of cars traveling over major roads in the City, and DDOT posts maps with the results of these annual traffic volume studies. These maps show that traffic volumes along Maryland Avenue have remained generally steady between 8,500 and 9,000 cars per day between 2011 and 2014 (the most recent year for which data is available). Note that these maps also show that traffic along Maryland Avenue is much lower than traffic along other routes in the area, like New York Avenue (52,400 cars-per-day in 2014), Pennsylvania Avenue (24,700), and South Capitol St. (31,700).

And these data show that an increasing number of people in the area are commuting by foot, and that people moving to the District are less likely to own cars than in the past:
88% of new DC households are car-free
U.S. Census Bureau American Community Survey