An ex of mine's uncle worked for 40 years as a track engineer for a railway company in Tokyo. There, the trains cannot be stopped for any longer than absolutely necessary, and the engineers were/are frequently called out to inspect and help clean up the track, with a claw-type pick-up tool and a bucket. Hit at 100kph and go under the wheels - it can be very messy. And I'm not talking once or twice here, it happened several times a year.

It's possibly even worse being the driver, but it always struck me what an utterly horrific job that must be and wondering what stress-related illnesses it would produce in the affected employees.

edit: I should clarify that any large body parts are collected by the police or medical personnel. The engineer's job is to certify the integrity of the track and clear it of foreign matter, washing it down too if necessary.