There's a game called moto chaser which looks a bit Road Rashy in the screens, not tried it myself but it's only 0.59p.
Actually having read the reviews you shoud probably avoid, have you tried playing RR1-3 on the genesis emu, There was also a game called Skitchin' for genesis that was like road rash only on roller skates, and you had to cling to the back of cars to build up speed.
My iPod isn't jailbroken. I had Skitchin' on the UK megadrive, back in the day. It was pretty good but no Road Rash.
