An injured pet can be unpredictable. When they suffer pain, they react instinctively. Even though you may be trying to help, you could get bit.
If you have to move an injured dog, you may consider making a muzzle to prevent your dog from biting out of fear or pain. Any strong material will do. Tear it in strips about 2" wide. Using the middle of the strip, wrap around your dogs muzzle. Bring the ends under his chin and tie snugly around the back of this head, just under his ears. Be sure not to cover or seal off his nose. This will make it safer for you to handle your pet.
You can move him on a blanket, holding the sides securely, to a vehicle to transport. If you can, cover your dog to keep him warm. Covering can also sometimes help calm a frightened animal.
As soon as you have your dog stabilized, call your vet and let him know you are on the way. This gives them the opportunity to prepare for his arrival. And do this BEFORE you are driving down the interstate at 75 mph! :+)
Taking these simple steps can prevent further injury to your dog and prevent any injury to you as well.