A utility trailer provides a frame defining a forward open bottom work space, a medially rearward deck and a rearwardmost extendable impact attenuator. Hitch structure encloses the forward portion of the work space. The impact attenuator is deployable spacedly rearwardly of the utility trailer in work site mode and provides frictional, mechanical and inertial devices to attenuate a forwardly directed impact. Additional impact attenuators extend between the hitch structure and a vehicle in towing motion. Plural jacks provide work site leveling and positional stability. The utility trailer provides an arch supported hoist to service the workspace and carries signs to provide traffic information and direction.