Chains that secure loads on public highways must have what requirement?

Chains that secure loads on public highways must have a proof test rating to ensure their strength and reliability. A proof test rating indicates that the chain has been tested to meet specific safety and performance standards, which assures that it can safely handle the loads it is intended to secure. This is essential for safety on public highways, as inadequate or unreliable securing mechanisms can lead to accidents, injuries, or property damage.

The proof test process often involves applying a force greater than the rated load capacity to verify that the chain will not fail under expected conditions. It provides confidence to users and regulatory authorities that the equipment utilized for securing loads adheres to industry standards.

While other options may pertain to load securing in various contexts, such as identification or insurance, they do not provide the critical assurance of structural integrity that a proof test rating delivers, especially in environments as demanding as public highways.