I realize that standards in…

I realize that standards in the automobile industry may have improved, but not all the cars on the road are newly built. The program required that cars older than 7 years were mandated to have an emission test. Would it not be more prudent to extend this period to, say, 10 years instead of cancelling the program altogether? On the roads, I see many cars that are older than 10 years, and do not believe it is a good idea not to check their emissions.