The best solution for the dangerous at-grade crossing of the Mount Vernon Trail at the George Washington Parkway is a tunnel. This tunnel will have a major impact on safety and can be built relatively cheaply. The Park Service is currently studying alternatives.
The location where the trail crosses the parkway is in Washington D.C. near the Virginia state line. The problem is discussed in Crosswalk is out of Place on George Washington Parkway by Robert Thompson of The Washington Post. Unfortunately when cars and pedestrians cross paths, car drivers usually win, with unfortunate consequences for pedestrians. When cars break suddenly to avoid pedestrians, the result is often a wreck.
Gregory Billing who handles outreach for the Washington Area Bicycle Association is advocating installing a High-Intensity Activated crosswalK or HAWK signal. The system combines a beacon flasher (a light that flashes periodically) and a traffic light. This solution would make the parkway more dangerous. The system brings cars to a halt. The Parkway has hills and blind spots. Cars traveling at fifty miles per hour will not be able to stop safely. A bridge would solve the at-grade crossing but clutter the natural scenery.
A combination path/tunnel would work best. This would include a path that travels below grade (at a level below the surrounding ground) for up to one-quarter mile in each direction and a small tunnel directly under the road. The path would have a slight grade that would not change the current topography. The path/tunnel has many advantages. Trail users will no longer have to brake for crossing bicyclists. Drivers will no longer have to watch for crossing bicyclists.
While there will be some construction costs, bike tunnels are narrower and cheaper to build than motor vehicle tunnels. The Transportation Research Board indicates the entire project could be built for between $500,000 and $1 million. While this is not inconsequential, it is a small sum to pay for safety. The costs for the tunnel should be shared between drivers and trail users. While funding is tight, this solution is a win/win/win for bicyclists/pedestrians, nature lovers, and drivers. In any increasingly politicized transportation environment, this is a rare occurrence.