Road Barriers and Ramps If the BorderTransportationSystem uses the super highway, high-speed rail, Mag Lev system then individuals will be allowed to drive his or her vehicle on the system and then exit where needed.  This poses a problem in that a person may exit on either side of the border, which tends to defeat the intent of the border security that is built into the system.  Thus the second and more acceptable solution of only high-speed rail and Mag Lev be used.  This solves many technical problems and also provides a secure way to assure that a person going from point 'A' to point 'B' can only do so. Since no drive automotive traffic would be allowed, the only way to bring a vehicle would be to load it on a Auto-Carrier, and that Auto-Carrier will be programmed to ONLY exit at the preprogrammed exit ramp, be that on the U.S.A. or Mexican side of the border.  No border inspection would be needed if the entry is in the U.S.A. and the exit also is, or visa versa; but if the entry / exit is across the border, then the Border Patrol will used. Index of ... Amtrak Auto-Carrier - Wikipedia