I met the IA at CSX who is responsible for building their positive train control system mandated after the CSX 8888 incident. We sat next to each other often on our commute from Marine barracks in Okinawa to the planning center for Fukushima. Sounds like trying to design something roughly as complex as designing an automobile, with plenty of prior art in metallurgy, materials, and basic machinery (bearings, screws), but having never seen a vehicle with 4 wheels before.

http://en.wikipedia.org/wiki/Positive_train_control

http://en.wikipedia.org/wiki/CSX_8888_incident