If you work near the White House, don’t have a car, and want to keep your commute under an hour, you could live in Gaithersburg, Md., or Reston, Va., both about 20 miles away.

But you'd have trouble doing the same from just across the Anacostia River in neighborhoods near the southern tip of the District, roughly seven miles away, or from close-in areas of Prince George’s County.

Metrorail, buses and regional commuter rail create an elaborate network of transit accessibility for the region. But while several wealthier neighborhoods and suburbs have relatively easy access to job centers, many lower-income neighborhoods on the eastern side of the District and across the border in Maryland are more difficult to reach.

Each of the colored regions on the map above, called isochrones, represent a different range of places you could reach in within a certain amount of time. Starting from the White House, for example, most of downtown Washington is accessible within 15 minutes (the dark-blue area on the map). The next region, in yellow, would take up to 45 minutes to reach, and the red areas would take up to an hour to reach.

The estimated commute times on these maps are based on transit schedules, which represent ideal road and transit conditions, as opposed to actual traffic levels on a given day. For more details on the modes of transit included in this analysis, see the methodology below.

[ When commuting in the D.C. region, distance doesn’t tell the whole story]