Recent train wrecks and people getting killed by trains have been in the news, becoming a major headache for America's railways. The wrecks and rollovers might be mitigated if a way were found to make the railroad tracks "feel" the trespassers or blocking objects. The idea would work like this:
1) Person or object is stuck on the tracks or trespassing.
2) Sensors/ detectors lining the tracks, or cameras, detect the person...