If you find an injured badger call the RSPCA immediately on 0300 1234 999 as expert help will be needed- do not try to handle the animal or approach it. Remember it is a wild animal, at best frightened, at worst frightened and in pain and likely to try to escape if approached.
Make a note of where the badger is as hopefully it may well be released back to that same spot. If you can watch from a safe distance do so but never put yourself at risk from other traffic. Should the badger move off try to see where it goes as you will need to inform the RSPCA.
If you find a badger in a snare do not attempt to release it, wait for the RSPCA. Cutting the snare could cause a severely injured badger to run off where it can’t be found and it could die from its injuries. All incidents of snaring should be reported as a wildlife crime to the police, take photographs on your phone if you can and if its safe to do so.
If you feel there is a traffic issue owing to the badgers location inform the police on 101.