Having seen two bridge strikes at Monty happen live, both of which hit the warning gantry approaching the bridge prior to actually hitting it, I have very little faith that a Google Maps warning about bridge height would achieve anything.
Not that I'm aware of, but would definitely explain it!
The problem with trucks are that they also require: minimum turning circle (eg hairpins), maximum load (old timber bridges and old roads), maximum widths (narrow roads or extra wide loads), residential zone exclusions (eg no trucks via certain suburban streets). In my country there are also statewide maximum truck speeds making Google time estimates inaccurate. There's also no consideration for the slower acceleration time of a truck, meaning that heavy (/city) traffic for a truck can add loads of time to a trip due to the stop/start.