You can just rename the PAI
_traffic.bgl ending to something else. That will disable your PAI
Another way of doing it is to create a new folder in your /scenery/world/scenery folder where your traffic files are, and place it inside that folder. That way the computer can't find it, and if you want to restore it all you have to do is pull it back out of that folder. That's what I did when I experimented with Traffic 2005.
Hope that helps