Sad...
There should a Sound, or siren, 100 or 200 feet on approach, along with light signals, measuring the height of vehicle. Red Light should flash.... along with the sound, before low head bridges...warning the driver, and there should be a detoure, allowing for a U Turn.
*Driver alone can not be blamed for such incidents.
This way alot of head ache, and possible loss of life, can be avoided. Specially endering the occupants of passengers cars, motorcycles following such a long vehicle.
In US you usually have height of the overhead bridges is marked in big letters on the bridge, and the drivers are trained on how to load the trucks and which routes to take for special loads. Some trucks come within inches of bridge ceilings, you can see, they have just 4 or 5 inches gap, barely enough to pass safely.
In Pakistan, too, I think the Motorway overhead bridges have Height of the bridges posted in big letters, but this new bridge has no markings, which a driver can read, 50 feet or so ahead. The truck drivers generally have the idea of the height of their truck, plus they can approximate the height of the load.