Courtesy Daimler AG.

The truck currently is in testing in Nevada.

While they may be years away from mainstream use, self-driving vehicles inched closer on May 5 in Las Vegas, where Daimler unveiled the Freightliner Inspiration truck.

Now in testing on Nevada highways, the 18-wheeler is the first autonomous truck licensed in the U.S. It combines collision-mitigation technology, such as radar-based adaptive cruise control and camera-based lane-keeping control, to provide an autopilot mode the driver can engage.

Not to be confused with a driverless truck, Inspiration cannot pass, merge or perform other complex maneuvers on its own, but Freightliner hopes to reduce driver fatigue, accidents and fuel consumption during long highway trips.