The past few times I've driven in New Jersey (in NJ for work, through NJ to get to fun places), I've noticed a sign that says "Restricted CMV."

To me this means HLA-restricted cytomegalovirus. I doubt this is what the DMV is telling drivers. Then again, it is New Jersey, so you never know.

(N.B. I did a quick search and discovered that NJ has a law requiring Commercial Motor Vehicle drivers to obtain a New Jersey Commercial Driver's License. Mystery solved?)