Abstract: Vehicle clearance anti-collision device includes an ultrasonic wave transmitter transducer and an ultrasonic wave receiver transducer for receiving waves generated by the ultrasonic wave transmitter transducer and reflected off an object disposed vertically above the vehicle. The device is mountable on a portion of a vehicle for transmitting substantially vertical ultrasonic waves. A computer device operatively associated with the ultrasonic wave transmitter and receiver transducers calculates the vertical difference between the object and the height of the truck and provides human-recognizable information to the operator of the truck as to the vertical clearance available between the object and an uppermost portion of the vehicle.