Hello, I have a question.

No one is being asked to slam on the brakes to avoid going 1 mph over.

They are being asked to drive the truck.

If a person is not paying attention to their speed, then they are not driving the truck.

It's like Van Halens "no brown m and m" contract rider. It isnt about the m and ms. Its "did you read and follow this document" about the needed electrical and weight requirements for their gear. They knew if there were brown m and ms then they needed tp double check on EVERYTHING else.

There are a million things that the company can't see. They can monitor speed, and if you can't follow this policy, which other policy are you not going to follow? Its not a skill issue, but behavioural.