Photo by techne on Flickr.

About one in seven workers in the DC area commutes to work via public transportation, higher than any other large American metropolitan area outside of New York. But where and how we take transit to work will make increasing ridership a challenge.

A new study by the George Mason University Center for Regional Analysis (CRA) reveals many surprising insights about the region’s transit commuters. Naturally, transit ridership is highest in the region’s core and near Metro stations. But there are also many well-heeled, outer-suburban commuters who use transit by choice, and low-income suburban workers for whom transit is a lifeline.

These two populations will present a challenge to the region as it continues to grow. With limited resources making a massive transit expansion unlikely, we’ll have to focus on smaller improvements in service, as well as encouraging transit-oriented development in suburban communities to encourage “reverse commutes,” taking advantage of excess capacity on Metro.

The percentage of transit users will stay the same

According to new data from the American Community Survey, 14.3% of Washington-area residents commuted to work via public transportation during the three-year period covering 2010-2012. We’re in second place among the 10 largest US metro areas, though first-place New York is far higher at 31%. Our transit use is higher than “older” areas that are often thought of as more transit-friendly, such as Boston (12%), Chicago (12%), and Philadelphia (9%).

But the overall share of Washington-area commuters who travel to work via public transit has changed little since 1990, and it is not expected to increase much in the future. In 1990, about 13% of all commuters in the area used transit. Looking ahead, a 2012 CRA study projected it will only be about 15% in 2040. While more people are now riding the bus and train to work, there are also more drivers, as well as more teleworkers and more people who walk or bike to work.

Where you live and where you work determines whether you use transit

Not surprisingly, more commuters use transit in some areas than others. DC residents are the most likely to commute via public transit, at 38.7%, followed by Arlington (27.2%), Alexandria (20.2%), Prince George’s (17.6%), and Montgomery (15.6%). Fairfax (9.2%), Charles (7.0%), and Prince William (5.7%) are the only other major jurisdictions where more than 5% of commuters use transit.


The percentage of transit users by county and CDP (Census-Designated Places). All images by the author.


The above map shows the transit commuter shares for the region’s major Census-Designated Places (CDPs), which include both incorporated and unincorporated cities, along with the shares in the balance of each county. There are nine CDPs in the region in which at least 20 percent of residents commute to work by transit: Chillum, Silver Spring, Suitland, Landover, North Bethesda, Wheaton, Rockville, Langley Park, and Bailey’s Crossroads.

While income levels vary greatly in these areas, they all have frequent, high-capacity transit service. All of them but Langley Park and Bailey’s Crossroads are located immediately adjacent to Metro stations, while those two areas both have frequent bus service and high shares of residents who do not have access to vehicles and are thus considered “transit dependent.”


Median earnings and transit commuter shares by CDP in metro area.


Conversely, CDPs in the region with the lowest rates of transit use are far from Metro stations. This group includes some of the most affluent parts of the region, like McLean, Potomac, Franklin Farm, and South Riding, as well as places with moderate earning levels such as Sterling, Chantilly, and Ashburn.


Transit share by place of work.


However, where you work is a stronger determinant of whether you commute by transit than where you live. Among those with jobs in the District of Columbia, 36.9% take a train or bus to work, compared with 22.0% in Arlington and just 12.0% in Alexandria. The transit shares are considerably lower for those with jobs in the inner suburbs, particularly in Fairfax County, where just 3.2% of workers take transit to work. For those who work in areas beyond the reach of Metrorail, just 1.1% of commuters use transit.

Transit commuters vary depending on where they live and work

For the whole region, transit commuters have almost the exact same median income ($50,203) as for all commuters ($50,288). For residents of DC, Montgomery, Prince George’s, Arlington, and Alexandria, those who commute by transit have either similar or lower incomes than do all commuters. But some transit commuters have higher incomes, like in Fairfax ($11,000 difference), Loudoun ($22,000 difference), and Prince William ($23,000 difference). Transit commuters living in these areas are clearly using buses and trains to access higher paying jobs in closer-in locations.


Median earnings summary for area commuters.


Meanwhile, those who take transit to jobs in suburban locations earn far less, while commuters working in either DC or Arlington earn about the same as all commuters. In Fairfax, Loudoun, Prince George’s, and Prince William counties, the median earnings for transit commuters is less than half those of all commuters. This disparity is largely due to the fact that many people who take transit to jobs in these outlying locations are lower-income, transit dependent workers.

Just 4% of residents living in the region’s outer suburbs (all areas outside of DC, Arlington, Alexandria, Montgomery, Prince George’s, and Fairfax) commute via transit. But they stand out from closer-in transit commuters in three key ways:

1. More than half (52%) of outer-suburban transit commuters work for a local, state, or federal government agency. By comparison, just 26% of all outer ring residents work for the government. In the inner ring, 32% of all transit commuters are government employees.

2. Outer-ring transit commuters have very long commute times, at a mean of 76 minutes. That’s almost twice as much as the mean travel time for all outer-ring residents of 39 minutes. Transit commuters in Fairfax, Montgomery, and Prince George’s have an average travel time of 52 minutes, while it’s just 37 minutes in DC, Alexandria, and Arlington.

3. Transit commuters from the outer suburbs use transit by choice, not by necessity. While 24% of the region’s transit commuters do not have access to a vehicle, fewer than 3% of outer-ring transit commuters have no vehicles.

What does this mean for future transit?

It’s clear that more people will commute via public transit where transit is readily available. As a result, it’s tempting to argue that the region can overcome congestion simply by aggressively expanding its transit network.

This approach ignores two critical points. First, while some expansions are likely to occur, financial and political realities will prevent many large projects from being built. Second, the current profile of transit riders offers many opportunities to increase ridership simply by increasing service or developing near existing transit.

There are three things the region’s already doing that will likely boost transit ridership:

  • Increasing the number of seats and frequency of service on existing suburb-to-core transit routes. To their credit, WMATA, MARC, VRE, and regional bus operators are all already working to expand the capacity on their existing routes, but more can be done.
  • Increasing commercial development around outlying transit stations. This will allow more people living in the region’s core to “reverse commute,” making use of excess capacity in the transit system. Proposals to relocate the FBI headquarters to Greenbelt or Springfield, along with Prince George’s County’s plans for the southern Green Line are excellent models for this approach.
  • Encourage transit-oriented development (TOD) around future rail transit. There are already a number of examples of TODs in the region that were planned around future transit lines, most notably King Farm and Crown along the planned Corridor Cities Transitway in Montgomery County. Even if proposed high-capacity transit lines do not materialize, these types of developments can encourage expanded commuter bus service and can limit non-commuting vehicle trips by locating shopping and dining closer to where people live.


While these approaches are helping the region battle its legendary traffic congestion, it’s impossible to ignore the prediction that more than 75% of the region’s commuters will still drive to work in 2040. And the region will have several hundred thousand more residents by then.

If the Washington metro area continues to grow in the same way it has before, it’s reasonable to expect that congestion and its related problems will cause residents and businesses to leave. In order to remain competitive, our region clearly must do more to expand the appeal of transit.