In the motorcycle community (at least in my area) we call people like that squid, both because they go "SPLAT" like a squid when they hit the ground and because it's an acronym for "Super Quick Until I Die".

The squid have been out en masse since it started getting warm out. Sometimes I wish I was as invincible as they seem to think they are, it IS hot and uncomfortable wearing leather in 80+ degree weather. Too bad its more uncomfortable to leave skin on the asphalt.