Seems like it would be really easy to implement. Jumping would help with some sticky situations where you, hypothetically, find yourself stuck on the track between two coaches and can't get out without restarting the service/scenario.
Or even being able to press and hold a button that will wormhole you to the nearest platform when you get stuck.
Actually for that there's CTRL+0, which immediately takes you to the last cab you were in. Doesn't work if you haven't sat in a cab anywhere yet, if course. I agree we should be able to jump, for some reason I always find myself trying to. It's just kind of standard in video games I guess.
