The thing of it is- after a few moments, all the drivers started moving again as if..nothing much happened!
“all the drivers started moving again as if..nothing much happened!”
Probably not. They were likely thinking they need to haul ass and get off that bridge in case it collapses.
I think it would occur to me to get off the bridge as soon as possible, either on foot or vehicle.
A motorcycle’s suspension — especially a dirt bike — would absorb a lot of the up and down movement but the side to side movement would be tricky and the rider would have to compensate much as for a sudden crosswind.