RIB MOUNTAIN, Wis. (AP) -

The Wisconsin State Patrol plans to increase its use of air support this summer to crack down on speeders.

It's part of a series of initiatives by the Department of Transportation to improve safety on Wisconsin roadways. DOT Secretary Mark Gottlieb says speed is a factor is about 30 percent of traffic fatalities in Wisconsin.

He says the DOT will mobilize the State Patrol Air Support Unit on a regular basis this summer. The unit includes four aircraft and 12 pilots who will clock suspected speeders and relay the information to troopers on the ground.

Gottlieb says more than 400 law enforcement agencies will be patrolling roads during the Memorial Day weekend. Daily Herald Media reports an average of nine people have died in traffic crashes statewide over the holiday weekend.