two of the largest ground vehicles ever built, including automatic load-leveling systems

The two crawler transporters of Kennedy Space Center's launch complex are the largest ground vehicles ever built. Each 6-million-pound transporter can carry a 12-millon-pound Saturn V rocket and mobile launcher combination several miles to the launch pads. Each transporter is equipped with jacking, steering, and automatic load-leveling systems. Traveling at top speeds of 1 or 2 miles per hour, the transporter has sixteen traction motors driven by diesel engines. The motors are mounted on four trucks with two belt treads, each the size of a Greyhound bus.