Whoa whoa whoa. You are getting it wrong. The size reported by your Amherst document is the maximum width, not the body width.
I have an idea of the importance of this distinction, and I could go at great length explaining it. But the linked document reference the AASHTO's Green book as a reference. And if that manual says that 10-foot road are ok in one chapter, and acknowledge the vehicles dimension in another, chance are that is ok. Obviously, if you think it is not, you have to demonstrate they are wrong.
Full disclosure, I know nothing about traffic engineering and I'm an average driver. This is the reason why I check expert sources and not the first document found on the internet...
I have an idea of the importance of this distinction, and I could go at great length explaining it. But the linked document reference the AASHTO's Green book as a reference. And if that manual says that 10-foot road are ok in one chapter, and acknowledge the vehicles dimension in another, chance are that is ok. Obviously, if you think it is not, you have to demonstrate they are wrong.
Full disclosure, I know nothing about traffic engineering and I'm an average driver. This is the reason why I check expert sources and not the first document found on the internet...