There is a way around this problem that on the surface sounds fantastic and improbable, but is actually practical.
In modern airport concourses, there are “moving sidewalks” that efficiently carry a high volume of pedestrian traffic long distances. They are a marvel, because otherwise pedestrians would have to walk several congested blocks, with frequent clogs of groups of people. Instead, there are two moving sidewalks, and a wide, almost empty area between them for anyone else, such as courtesy vehicles.
This could be applied to multi-lane bridges, and would keep traffic flowing at a constant rate of speed.
The two normal middle lanes would be for heavy vehicles, and when traffic was light enough for faster speeds for passenger vehicles. Drivers who went onto the moving lanes would just put their vehicle into neutral, then park, and ride the distance of the bridge. The only oddity would be for special pull out lanes at the end of the bridge, so vehicles with engine problems could coast out of the flow of traffic.
This technique could also be used in bottleneck sections of freeways, that regularly cause traffic jams.
Importantly, in either case, the rolling roads would only be used during times of peak congestion.
One of the thing that annoys me most about the east is the proliferation of toll roads. That is what gas taxes are for. If a state has toll roads, then they should have no gas tax and vice versa.