There are some low-clearance bridges around the world that routinely get hit by trucks, just because they are a few centimetres lower than a standard clearance for some reason. After the third or fourth time they get hit, you'd have to imagine someone at the city council saying "why don't we raise that bridge?" and someone else replying that it would be too disruptive to existing traffic, plus it's not a simple matter of jacking it up and putting in some chocks to keep it there. Bridges are complicated.
So why don't they just dig a trench underneath the bridge to increase the clearance those few extra centimetres? It's much simpler and cheaper, and it could be done in one day. Problem solved. At least until a slightly taller truck figures he can duck under the new slightly-higher bridge.
Mokalus of Borg
PS - They should probably routinely lie about bridge clearances.
PPS - Though they should only under-report them, obviously.