This was a a really though one.
The speed of the game doesn't give me enough time to get my bearings and get used to the controls and I end up dying before I even understand what happened :( I first tried as 1 player but my brain is not fast enough to process the switching in time so I changed to 2 players which I didn't fair much better as the characters didn't move the way I thought they would. lol
I think the ideas is really good and fun and works very well with the theme but perhaps start the game at a much much slower speed with much less hazards and as you go through "sections", like milestones, then you increase the speed a little more each time and increase the total hazards on the road since this game has the "arcade" feel to it where you play until it is impossible to beat.
Really cool idea, lovely aesthetics, nice music and over all a really well done game.