Transit in the DC area is not just for urbanites. Residents of counties farther from the center of the region ride as many miles per day on transit as those who live closer in.

Daily miles traveled per household. Table from COG report on cycling and walking.

Some drivers and and politicians in exurban counties complain that their counties’ gas taxes are paying for urban transit riders. In reality, it’s just the opposite: denser areas subsidize the long-distance travel that sprawl requires. 

Only a small part of transportation revenue (22% in Maryland) comes from the gas tax. And drivers get most of that back because gasoline is exempt from sales tax. Most money spent on roads comes from taxes on income, real estate, general sales, and automobile sales and registrations. These taxes don’t go up if you drive farther.

The above table comes from a new Council of Governments report on cycling and walking. The report used data from the agency’s 2007-2008 Household Travel Survey to calculate the daily distance traveled per household by each means of transportation.

By this measure, transit gets the most use not in DC or Arlington but from residents of Prince William County. They ride 6.6 miles per day; Montgomery is second at 6.4. DC clocks in at 5.6 and Arlington and Alexandria, at around 4.5 miles a day, are behind Fairfax and Frederick Counties.

It’s not that the region’s outer reaches aren’t automobile-dependent; residents of exurban counties do 90% of their travel by car. It’s that spread-out land use patterns make them travel farther and force them to use cars for most trips.

When destinations are far apart, people take fewer trips on transit. But each trip is longer, on average, and the total distance on transit is about the same as closer in.   

The high driving rate in the DC suburbs does not make transit unnecessary. It only proves that the more highways you build, the farther people have to travel to get anywhere. The last thing we should be doing is forcing even longer trips.