Interval Sensors Proper interval spacing between rail units in the BorderTransportationSystem will be critical as the system gains popularity and more units are moving upon the tracks.  The goal is to eventually have one rail car pass a given point every 60 to 90 seconds, or the calculated stopping distance for the largest and heaviest rail unit used.  To do this there will be an need for sensors at appropriate intervals that can send signals via the protected fiber optic cables back to the main monitoring station's computer system. Index of ... Optimal Design of the Absolute Positioning Sensor for a High-Speed Maglev Train Real Time Monitoring of Railway Traffic using Fiber Bragg Grating Sensors Solutions for high-speed rail