A guy I drove with at a national freight company with a ton of trucks on the road put a blue light on his CB antenna that lit up when he pressed the mike. Since we had a different rig every trip. this was his way of identifying himself. We drove out of Buffalo NY to points East and spent a lot of time on the NY Thruway. He got a ticket from the State Police for displaying a blue light when he was not a volunteer Fireman or driving an emergency vehicle. He asked the Trooper why he did not ticket all the Canadian rigs that displayed blue lights and the Trooper told him that they could not be given tickets because the lights were legal in Canada.
It is sort of like the steel coil law. If you have a CDL issued in NY State and are going to haul steel coils, You need to take and pass a test on the proper loading of steel coils and get an endorsement on your license, just like the endorsement for doubles and triples, hazardous materials, tankers, passenger buses, and tow trucks.
The problem with the steel coil law is that it is a NY State law and very little steel coil is made in NY anymore, so most of the steel coil that moves through NY is driven by out of state or out of country drivers who are not required or even able to get the endorsement. It is just one example of useless feel good legislation that burdens people without accomplishing anything.