Class B: Driving on Parkways and Tolls

We have driven in all 48 lower states in the past 10 years. Alaska this summer). We have not had problems with tolls and parkways. We are just under 10 feet tall, so not much problem with low bridges, just watch the signs. In Delaware, the toll lady got out to count how many tires on the ground (4), so we paid the car rate. Crossing the Mackinac Bridge, the lady charged us more because we "slept in the van." In more recent years we get a toll tag, ez pass, etc. for the area we are visiting. In California, it saved us waiting in a long line to cross some bridges. I wish there was a nationwide tag.
As others already noted, be aware of restrictions for tunnels, on ferries, they usually want the tanks turned off.
Happy camping.