A 35-ton tractor can pass a 33-ton-maximum brick bridge now. That's probably due to the new axle load code, but this new restriction is not shown in the tile info window. That's irritating for new players (and for me).
Was all of the tractor on the bridge? The weight restriction is for the fraction of the convoy that is on the bridge at any given time. For this reason you can run heavier convoys over lighter bridges as long little of the convoy is ever on the bridge at any given time. Best seen with trains where you can make a multi thousand ton engine go over a 800 ton limited bridge as long only a small part of it is on a bridge at any given time. This applies to both bridges and elevated ways. In the case of trams it uses the weight restriction of the underlying road elevated way or bridge.
It's a tractor with four trailers, that makes it two tiles long; the bridge has three tiles.
Apologies for the delay in replying to this. Can you upload a saved game in which this issue can be reproduced?
I am currently reviewing older bug reports; can I ask whether anyone can still reproduce this or whether it should be marked as solved?