I was thinking about this posting and knew that there was something in the back of my mind..it finally jarred loose. Note that tunnels are arched. A person that is not 100% focused on the task at hand will shy away from that right entry. The tunnels are all singe lane each way, and they are not w-i-d-e lanes, either. A driver will easily find themselves over the double yellow, with oncoming traffic and perhaps a transport or another RV'r in the same mind-set, coming at you. Chances are you will shy away as you enter the tunnel...get back over ASAP.
Gary Haupt