I’ve already written about what a bad idea trusted traveler programs are. The basic security intuition is that when you create two paths through security — an easy path and a hard path — you invite the bad guys to take the easy path. So the security of the sort process must make up for the security lost in the sorting. Trusted traveler fails this test; there are so many ways for the terrorists to get trusted traveler cards that the system makes it too easy for them to avoid the hard path through security.