Not sure if this has been well discussed here, but I thought this video was pretty interesting. It has to do with the proper setting of speed limits and shows that a speed limit that is too low can be dangerous. It is a Canadian production, but seems to have been translated into something close to English.
I think these sorts of things are worth considering (and maybe evening discussing without mentioning street racing, relations with animals, or other activities illegal in 48 States).
http://youtu.be/2BKdbxX1pDw