Best to have the map to the bridge before crossing it.
If you will have to release the seatbelt and the seatbelt is near your holster, you might want to keep your hands on the wheel and state:
"Officer, my driver's license is in my wallet, and I would have to release my seat belt to get it out for you. I'm licensed to carry, and it's in a holster right by my seat belt buckle. Tell me what you'd like me to do."