The one they are trying to push through here in California is for 8 counties. It will require testing for all pre 76 vehicles at change of ownership and testing every 2 years forever. Currently all vehicles 76 & newer require testing.
Just who is going to establish the test standards for Model A's, Hudsons, our trucks, modified vehicles, etc seems to be unknown. Our illustrious "Green Govenor" travels on a private jet from Sacramento to his home in So Cal and back 4 times a week. He causes more polution in one week than all of our vehicles in a lifetime.
Fred

1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine