A Cal-Trans truck on Interstate 580 was “carjacked” at gunpoint Saturday morning by the driver of a BMW who moments before had smashed into the vehicle.

At approximately 5:25 a.m. a line of Cal-Trans trucks were traveling westbound on Interstate 580 in Castro Valley in preparation for a “sweeping detail,” according to the California Highway Patrol. The rear attenuator truck, displaying a ”lane closed” sign, was slammed into by a black BMW. After the collision, a second Cal-Trans truck stopped to help out. The driver of the BMW then hopped out and pulled out a handgun and took off in the second Cal-Trans truck, traveling westbound on Interstate 580 toward Oakland.