Engine and Rail Car ID To make the system work each rail car and each engine must have an ID number that can be read at high-speed by rail-side sensors.  The BorderTransportationSystem will use the ID numbers to track the location of each unit, track loads, and decide on the proper exit of the unit, either on the U.S.A. side or the Mexican side of the Border.  We have existing sensors, but need to upgrade each to handle the very high speeds of the Mag Lev and the High-Speed trains. Index of ... Automatic equipment identification Automatic Equipment Identification, or AEI, data tag Rail Technology and Signaling Solutions