Development of vehicle-following distance warning system for trucks and buses

The development of a vehicle-following distance warning system for trucks and buses is discussed. The details of this system are described. The trial productions of a final specification are tested by private trucks. The result is very satisfactory. Test drivers set a high value on these systems. Three-beam laser radar is selected as the method for sensing vehicle-following distance. Laser beams are directed forward from this unit and return by reflecting off the vehicle ahead. The vehicle-following distance is calculated from the amount of time required for beams to go and return. The warning is issued by a lamp and buzzer when the actual vehicle-following distance becomes less than the safe vehicle-following distance.