CommuterRun

Depends on the road design of the bridge, how heavy traffic is, etc., but I would most likely find a gap in traffic that I could establish the lane position I wanted before reaching the bridge, then ride across. If the design of the road and traffic doesn't allow passing while on the bridge, then faster traffic will just have to slow and wait to pass until after we get off the bridge. When we leave the bridge I would likely shift to the right to extend the courtesy of ease of passing if the design of the road allowed that, and I determined it safe for me to do so.

I don't think the type of motor vehicle whose operator desires to pass is important. Actually I find the operators of large trucks to be among the most professional and courteous on the road. What is important is that the cyclist make themself visible from a distance and ride in a predictable manner that makes their presence and lane position blatantly obvious.