Part of the problem is with turn signals on tractors, which control the wagon. I've heard various safety groups say that most following vehicles don't notice the change in the lighting from "all flashing" to "one solid, one flashing" as is used by tractors. Following drivers do see the flashing lights, but after a few moments of watching them, they don't notice the change. Actually, it's probably better to use strobes as primary "flasher" and save the tractor turn signals for turn maneuvers. That change might be noted more by the following drivers.

I agree that depending on the visibility restriction that morning in the OP that cameras, lights, etc might not have helped. That's just a second guess. Don't know if it was 3 mis visibility, or 1/4 mi. visibility. If it was a 1/4 mile, I wouldn't be on the road with a wagon. That's "here".