I was amused and entertained by this video clip about fun-seeking young men who run a sort of 'go-kart on train wheels' on an old railroad track in California.
The only downside I could think of is, what happens if a train comes along at the wrong moment? I presume they only do this on older, disused railway lines . . . but what if they pick one that's still used now and again? The thought reminds me of the old Road Runner cartoons, where Wile E. Coyote has (usually disastrous) encounters with all sorts of trains - like this one.