LAS VEGAS (KLAS) — State Police said the driver of a car on U.S. 95 in the northwest valley was killed early Sunday when he hit an impact attenuator on an exit ramp.

The crash at 3:04 a.m. closed a portion of the highway near Elkhorn Road until shortly after 9 a.m. as the Highway Patrol Division investigated.

Police said the driver of a blue Honda was exiting northbound U.S. 95 at Elkhorn Road when he failed to maintain the marked travel lane, striking the impact attenuator.

Medical personnel pronounced the driver dead at the scene. The driver appeared to be alone in the car, a police spokeswoman said.

Impact attenuators are placed at the end of roadway barrier walls and serve as crash cushions, helping to reduce damage to drivers, vehicles and surrounding structures during a crash, according to the Nevada Department of Transportation.