Nutsa NHTSA being a national group, it might be some Feeberally coordinated thang.
There were some radio ads a few years ago where “safety groups” practically bragged about nationwide seatbelt laws as primary violations, and those got quickly pulled when it looked like opposition was quickly amassing. No sense in losing the 50-state legal tyranny, after all.
https://en.wikipedia.org/wiki/Click_It_or_Ticket#Illegal_Checkpoints_.26_Enforcement
Illegal in these states:
4.1 Arizona
4.2 Colorado
4.3 Idaho
4.4 Indiana
4.5 Massachusetts
4.6 Missouri
4.7 Montana
4.8 Nebraska
4.9 New Hampshire
4.10 North Dakota
4.11 Ohio
4.12 South Dakota
4.13 Utah
4.14 Vermont
4.15 Virginia
4.16 West Virginia
4.17 Wyoming
Eg. MA:
The provisions of this section shall be enforced by law enforcement agencies only when an operator of a motor vehicle has been stopped for a violation of the motor vehicle laws or some other offense.
Mass. has better laws in this regard than Texas. For shame, Texas.