What is the primary function of "chock blocks"?

Chock blocks play a crucial role in ensuring the stability and safety of vehicles during transport. Their primary function is to secure vehicles in place by preventing them from rolling or shifting while on a transport vehicle, such as a ship, truck, or aircraft. By using chock blocks, personnel can effectively safeguard against accidental movement, which could lead to accidents or damage to both the vehicle and the transport equipment.

Given the context, the other options do not accurately describe the primary role of chock blocks. While enhancing fuel efficiency, assisting with loading and unloading, and indicating cargo weight are important aspects of logistics and transport operations, they do not pertain to the specific function of securing vehicles.