Here if the bridge is on a slant there will be two cleance signs on either end of the bridge. Here if the bridge is under 14ft there is a larger advisory sign to warn truckers like this:

Here they usually put one rectangular sign over each lane if the bridge is slanted. The diamond one is usually used before the bridge as a extra warning.

Yeah the diamond shaped sign isn't used on bridges it's used before them but only if the bridge is under 14ft. Here I've noticed every bridge over the highway is over 14ft but on side streeta there are some under 14ft...

I think we only post them if the bridge is lower than 4.4m which is around 14 feet.

Here they are common but drivers reading them are not. Last year had 2 get stuck under the same bridge, even though it is signposted, has signs on the approaches and has signs warning trucks to use an alternate route. Last one almost made it all the way through, or at least the cab did, the full container body on the back was ripped off and torn in half for almost the entire length, and was slanted. Not to mention the municipal bus, roof collapsed back and all the windows were shattered.