Thousands use the road every year..RVs and transports and all the rest. I think the mistake many make is to not take the warning sign seriously. If you were asking me? I'd say...stop and clear traffic behind, drop your transmission into a low gear, flick on the emergency flashers and drive down. If a person is in a high gear and hasn't slowed down, then things are going to get dicey.
Here is a speeded up video from a tour bus. It is horrible to watch but skip to 3:21 to 3:35. That will show you the actual roadway.
https://youtu.be/Mqm0tvvrn2Q Gary Haupt