Some of our roads are getting bumpier—on purpose.

About 600 miles of our two-lane highways have been made bumpier so far by the state transportation department. It has happened when those roads have been resurfaced or rebuilt. The bumps are in the middle.

Department Traffic Liaison Engineer Jim Brocksmith says rumble stripes have worked so well on the edges of those highways that the department wants them in the center line too. It’s partly an effort to wake up drowsy drivers and partly an effort to make roads safer in the rain. "It helps make that stripe visible on rainy nights…A big complaint we’ve gotten over the years is that on rainy nights people say they can’t see our striping," he says.

It’s too soon to measure how much safer the center-line rumble stripes make Missouri roads. But Brocksmith says studies in other states indicate they reduce head-on and sideswipe crashes by about 25 percent.

The department started putting rumble stripes on the edges of highways in 2005 and center-line rumble stripes on two-lane roads in 2007. The stripes are not installed in urban areas because of the noise concerns they cause. But they are included on any other resurfacing projects on major two-lane highways. .

Upload BP’s interview with Jim Brocksmith (7:41 mp3)