How safe is it to bicycle on interstates?

A study of the nearly 4,000 bicycle fatalities in the United States between 1994 and 1998 found that seven bicyclists were killed on rural interstates. All seven riders were riding in the travel lane rather than on the shoulder. Twenty-eight riders were killed on urban interstates, in all cases they were riding on interstates that were legally closed to bicyclists.

Although people's first reaction to the idea of riding on interstates is often negative, there are numerous reasons why it makes sense in many locations. First, the interstate may be the only road between two points and bicyclists would otherwise not be able to reach certain destinations. Second, interstate highways are built with wide paved shoulders (usually 10-12 feet) and a high quality surface. Grades are usually relatively gentle and consistent, as are the curves. This means that sightlines and riding conditions are very good, especially when compared to alternate routes on non-interstate routes that might have tight curves, no shoulders, steep sections, crumbling surfaces and still have traffic going at 55 miles per hour or higher. Third, the number of cyclists using interstates is quite small and usually limited to riders who are more experienced, confident, skillful and aware of traffic hazards. The specter of eight-year-old children riding on busy interstate routes is not borne out in reality. Fourth, more and more sections of the interstate system are being treated with rumble strips to alert drowsy motorists if they stray from the travel lane. Bicyclists are able to ride to the right of the rumble strip (which usually only takes up two feet of the shoulder) and thus gain some additional protection from errant drivers.

However, bike riding on interstates is not without danger. The powerful wind blast of passing trucks, the need to pass disabled vehicles using the shoulder, and negotiating high-speed on- and off-ramps are all challenges faced by riders using these roadways. The latter problem is partially addressed in design manuals such as the AASHTO Guide for the Development of Bicycle Facilities and the Oregon Bicycle and Pedestrian Master Plan.