Drivers on Interstate 70 in the St. Louis area may soon hear and feel new additions to the road during their commutes. But the rumbles are no cause for concern. They are designed to keep motorists on the road and out of the ditch, says Dr. Gary Spring, associate professor of civil engineering at UMR.

I-70 is the ideal location for the "rumble strips," says Spring, who is designing rumble strips with the Missouri Department of Transportation. The strips are designed for both rural and urban areas.

Studies performed throughout the country estimate that rumble strips reduce by 20 percent to 80 percent the number of accidents involving vehicles that run off the road. These raised, evenly-spaced pavement bumps are placed along the edges of roads to alert drivers when they start to veer off the road. Research done by Spring and several UMR graduate students shows that rumble strips are an added safety feature for motorists. According to Spring, almost 8,000 accidents per year in Missouri result in running off the road.

Working with MoDOT, Spring is designing rumble strips using general guidelines supplied by the Federal Highway Administration (FHWA). These guidelines are helping the project progress more quickly, says Spring.

The design of the rumble strips took shape based on the needs of the general motoring public, including the perspective of bicyclists. Existing research, including a FHWA survey taken in all 50 states, showed that most drivers want the strips to be as bumpy and loud as possible. For bicyclists, however, rumble strips that are too bumpy will be more harmful than helpful.

Spring created a design that would take both opinions into consideration. The new design is milled with five-inch grooves and seven-inch spacing. On freeways the strips will be 16 inches wide and six inches off the shoulder line. However, since more reaction time is needed in order to avoid accidents on most rural roadways, the strips will be located directly on the shoulder line and will be 12 inches wide.

"Most of our recommendations are in alignment with what the Federal Highway Administration recommends," Spring says. "They don’t want to dictate what a state will do, so they’ll be very general on what it should look like." A similar design has already shown effectiveness in reducing crashes in other states.

Missouri is among the 10 U.S. states with the worst road conditions. Rumble strips would increase the safety of the Missouri highway infrastructure, says Spring.

Spring will send his recommendations to MoDOT for approval. Once approved, the new rumble strips will be put into effect on most roads in Missouri. Spring says MoDOT has been anxious to get the final report and expects quick approval. -30-

NOTE: This release was written by UMR students Angela Dunnagan, a sophomore in engineering management from O’Fallon, Mo., and Jennifer Winkert, a junior in information science and technology from Raymore, Mo., as a technical writing class project.