An interface for connecting a calculator to a standard television, so that the calculator’s display can be re-displayed on the television. The system generally includes an on-board vehicle control unit for each vehicle and a base station control unit for making telephone calls to passengers in order to inform the passengers when the vehicle is a certain predefined time period andor distance away from the vehicle stop. The wall portion is made of a material forming the spacer, the shutter, and the drive portion. The invention also provides a motor vehicle bumper having such a beam.