More Houses, More Traffic

To Virginia legislators: Get to work. To Virginia commuters: Good luck getting to work.

NORTHERN VIRGINIA traffic is awful; it will get worse. Loudoun County's Board of Supervisors has zoned land to allow almost 37,000 new houses to be built in the county. On top of that, the county's Planning Commission wants to allow developers to build 28,000 additional homes west of Dulles International Airport.

Bad idea, according to the Virginia Department of Transportation (VDOT), which last week released a study on the effects 28,000 more single-family residences would have on regional traffic. VDOT estimates that the new development would create as many as 300,000 additional car trips every day. Expect bumper-to-bumper congestion for up to six hours daily on portions of Route 50, Braddock Road, Route 29, Interstate 66, the Dulles Toll Road and the Dulles Greenway, among others. And that's an optimistic scenario; VDOT's estimates assume that billion-dollar infrastructure improvement projects such as the Dulles Metro extension and highway widening in Northern Virginia will happen according to plans. Ameliorating the additional congestion would cost "easily" hundreds of millions of dollars more, the report says.

The rezoning proposal is now before the Board of Supervisors. The board should turn it down.

Even if it acts sensibly in this case, though, development will continue in Loudoun -- and in Fairfax, Prince William and beyond. The new commuters these developments create will use roads in Northern Virginia. That suggests, first, that Loudoun's Board of Supervisors should zone intelligently; the county hasn't devoted enough money or time to the road and rail improvements needed to accommodate growth that's already slated, let alone the demands 28,000 more homes would place on the region.

But the policy implications extend well beyond Loudoun. As the VDOT report makes clear, new homes in one county affect roads in neighboring counties. The state needs to get serious about transportation. Gov. Timothy M. Kaine (D) has tried to do just that and has been stymied so far by the Republican General Assembly. The latest study is one more piece of evidence in favor of a special legislative session to cope with the worsening transportation problems in the region and the state.