Those “rumble strips,” the raised patterns along highways that jar drivers to attention when they begin to drift out of their lanes, may be noisy, but some Douglas County residents believe the increased safety is worth it, researchers at Kansas State University have found.

Doctoral student Daniel Karkle and Malgorzata Rys, associate professor of industrial and manufacturing systems engineering, have been studying centerline rumble strips for years.

They’re the ones that run down the middle of two-lane roads, such as U.S. 40 in Douglas County. They’re designed to improve the safety of roads by alerting drivers they are drifting out of the lane.

The researchers have found that adding center line rumble strips have reduced fatality and injury crashes by 46 percent in Kansas, and crossover crashes were reduced by 68 percent, along with other benefits.

About 400 miles of two-lane highways in Kansas feature the rumble strips, Rys said, but the number is growing.

Karkle has found that the ones in use in Kansas can be noisy, ranging from 60 to 80 decibels, when at the minimum distance of 200 feet from the center line, as required by Federal Highway Administration standards for acceptable noise levels.

At the 60 decibel level, the noise would be about like a dishwasher running, and at 80, it would be comparable to a television set, Karkle said.

Rys said researchers interviewed people in Douglas County on U.S. 40 between Lawrence and Topeka, where homes are relatively close to the roadway.

“They say they can hear the noise, but they feel it’s more important to install the rumble strips,” she said, for the improved safety of the roadway.