Final answer:
The correct statement about overhead clearance is that cargo weight may change the height of your vehicle. Posted clearance signs may not always be accurate due to changes like road repaving, and clearance concerns apply to all types of vehicles, not just passenger ones.
Step-by-step explanation:
The true statement about overhead clearance is: c) Cargo weight may change the height of your vehicle. This is because the added weight can cause a vehicle to sit lower, potentially reducing the clearance under bridges, overpasses, or other overhead obstructions.
Meanwhile, posted signs for overhead clearance (a) may not always be correct, as factors such as road repaving might alter the actual clearance since the sign was installed.
Paving a road can actually affect clearance height under bridges or overpasses; as the road surface increases in height, the clearance decreases (b). Therefore, it's important for drivers of all vehicles, especially those operating larger commercial or freight vehicles, to be aware of their vehicle's height and to observe signage and take note of potential changes to posted clearances.
Clearance heights are not only important for passenger vehicles but for any kind of vehicle that could exceed the available height clearance (d).
Therefore the correct answer is c) Cargo weight may change the height of your vehicle.