What classification of disability are we talking about? That would make a difference in the answers you get.
I teach Developmentally Handicapped (DH) and LD kids. Our kids either wait until they are 18 to get their license, so they don't have to take Driver's Ed, or take it with the regular kids. We teachers then work with the Driver's Ed teacher and help the kids study, and read their tests to them.
I'm sorry I couldn't be of more assistance to you.