A curious use of self-selection at the airport

At Midway Airport, TSA signage splits passengers entering the terminal into three groups: families and passengers with special needs, "casual travelers", and "expert travelers". The first category needs no explanation, but the demarcation between the latter two--or even what it means to be an "expert" at traveling--is unclear.

Nevertheless, after a few moments of thought, I moved to the "expert" line, which moved more quickly than that for the "casuals". Perhaps there is something to it, or perhaps the line is merely faster because fewer people will self-identify as "expert" anything. One would have to sit at security for a couple hours and count the number of fumblers and nincompoops going through each line, or better still, time each passenger's delay at the metal detector, to be sure.

There was no check for expertise, and no meaningful social sanction--not even a dirty look--for fumbling. Plainclothesed TSA workers didn't watch for "experts" who stood still on Midway's famous "moving walkways" ("Caution, the moving walkway is ending...") We can't rely on people even to not smoke on the sidewalk or in doorways, or to control their conversational volume; can anyone explain why in this situation they should be expected to meaningfully segregate themselves by ability to efficiently pass the security screening?