Highway shoulders can become bus lanes, but it takes work

Why not let buses drive on highway shoulders to get around congestion? According to a regional task force, that can be done, and it does often work, but it’s not quite as simple as putting a sign up and saying “let’s do it”.

With pressure mounting to stretch dollars and improve mobility, creative ideas like putting buses on shoulders are getting more attention. Maryland is considering the concept on I-270 and MD-5, and Virginia hopes to have a pilot project on I-66 in Arlington by 2014.

These would add to the handful of locations around the DC region where buses are already allowed to use the shoulder. The most notable example is the Dulles Access Highway inside the Beltway.

The main complicating issue is that highway shoulders are usually too narrow and not free enough from obstructions to immediately open them up to buses. Interstate highway standards call for 9-foot shoulders, but you need at least 10 feet for a bus, and really 11 feet is preferable. So a typical highway shoulder will have to be beefed up in order to be used as a bus lane.

That’s a lot easier, and cheaper, than just about anything else you could do. But it’s still a construction project that needs to be planned and funded.

Minneapolis has an extensive network of over 300 miles of shoulder bus lanes on highways. But it’s taken them over 20 years to get there. They have a continuous program that adds a few miles each year. They started with the low-hanging fruit, and have worked up to more complicated stretches.

That’s the idea behind Virginia’s pilot project on I-66. At first, the section allowing buses will be short. It won’t be a busway so much as a spot where buses can jump ahead of a queue of cars. But over time VDOT could lengthen the segment and provide a larger benefit.

For safety reasons, buses are usually only permitted to go 35 miles per hour when using shoulders. Still, that’s enough to get by the worst congestion. If traffic is moving faster than that, buses just stay in the regular lanes.

Cross-posted at BeyondDC.