The design and construction of a road and rail simulator for the dynamic testing of automobiles, trucks, trailers and railcars is described. The vibration test facility features a 1.3 million pound (600,000 Kg) seismic mass supported on air mounts. Specimens up to 100,000 pounds (45,000 Kg) can be mounted at floor level on six hydraulic actuators with force ratings of ±200,000 pounds (900 kilo Newtons) vertically, and ±110,000 pounds (490 kilo Newtons) horizontally. The six channels of actuators are programmable and can be run closed loop with tapes derived from field input data. 135 channels of static data and 30 channels of dynamic data can be recorded and manipulated.