PB, I smashed a finger today so I ain't typing too good but I will try to help you with your request.

GA or any other state can pass laws as they see fit and enforce them.  Consider CA's laws concerning vehicle emissons that affect the older refers.  Do you think they haven't been able to enforce those laws on the interstate trucks that cross into CA?  Other laws like bridge laws that vary from state to state are another example of the way a state can impact interstate transportation. 

As far as the GA laws regarding recaps, here is a quote that may shed some light on the issue for you: 

The law in my state of Georgia allows recaps on all wheels except the front. It's time to prohibit them on all wheels. I have seen a driver lose control and run off the road after hitting one of these tire pieces. I also have witnessed another driver hit one that ripped the trim off the side of his car. And I hit one of those tires, damaging both my steering column and transmission linkage. The Firestone situation is serious and should be dealt with. But it's ridiculous to allow inferior truck tires to separate, leaving large and dangerous obstacles on our highways, with no apparent accountability from the trucking companies.

Charles Hollomon
Stockbridge, GA