The Iowa Department of Transportation has recently done some maintenance to some highways in Greene County.

DOT District 1 Maintenance Manager Bob Ellis tells Raccoon Valley Radio that crews applied an oil/water mixture called ESS1 to the shoulders on US Highway 30 and Iowa Highway 17. He says the black material is used to prolong the life of the concrete shoulders of those highways from drying out due to the asphalt overlay that was done on those roads. He explains that this material has water mixed in so that the water evaporates out which allows the surface to harden and not crack or break apart. 

Ellis adds that this type of maintenance tends to be done every two to three years to maximize the lifespan of the road and shoulders.