The Lincoln (Neb.) Journal-Star reports that fatigue-related accidents in Nebraska dropped from 565 in 1998 - the year before the state started installing the rumble strips - to 488 last year.
Rumble strips are a series of bumps on a road's shoulder that "rumble" loudly when a car rolls over them, jarring awake sleepy drivers who may have drifted onto the shoulder.
The trips were added to the 429 miles of Interstate 80 east of the Wyoming border at a cost of $1.5 million starting in 1999. The only parts of interstate in Nebraska without the rumble strips are urban areas and planned construction zones.
I-80 isn't the only highway in the state with rumble strips. They have been included on four-lane expressways since the state Legislature created the classification in 1988. The state Department of Roads plans to include rumble strips on the other 600 miles of designated expressways, as well.