Existing Railroad Crossings There are a few railroads that cross the border from the U.S.A. to Mexico, and these will have to be crossed by the new BorderTransportationSystem.  At these junctions, it will be recommended that there be physical junctions so that passenger and freight coming from or going to Mexico can be routed onto or off of the BorderTransportationSystem.  New Border Patrol inspection stations may not be needed if the junction is located within turning radius of the existing inspection stations.  The turning radius will have to be approximately 90 degrees as it is connecting a north / south track with an east / west track. Passenger trains will have to be stopped, and the passengers will have to transfer from the standard rail trains to the Mag Lev train, unless both trains are Mag Lev, in which case there will have to be a new Border Patrol stop where agents can board the trains and inspect documents. Index of ... CSX de Mexico - Shipping Rules and Regulations First New Rail Bridge to Mexico in More Than a Century Rail crossings - Wikipedia