Injured Badgers/Foxes need to be approached with caution and should not be handled by inexperienced people.
If you come across one at the side of the road that needs attention call your local wildlife rescue or the RSPCA. DO NOT TRY TO MOVE IT YOURSELF. They are capable of giving you a nasty bite. This also applies to badger cubs and fox cubs. Never try to put an unconscious badger/fox in your car or even your car boot.
If the badger/fox is on the roadside you may need to inform the police. Do not put yourself at risk and don't try to move it. If you have any means of alerting other road users like putting your hazard lights on or standing nearby with a torch or high vis jacket do so. If it tries to crawl away just keep an eye on where it is crawling to until help arrives.