HWD is used to measure deflection of thick highway pavement. The device mounted on a two axle trailer designed specially for determining structural information of heavy-duty type pavements. The device have Hydraulic Breaker, 2-Cylinder 18 Horse Power gasoline engines with 12 volt Alternator permits high speed and independent operation of the tow vehicle. 4 drop automated sequence in 30 seconds, data capture from 1-35 drops at each location with up to 35 forces.