Voluntary. I choose not to because I know what line I belong in. I am in this line every week at FLL.
I find it funny that in all the major airports I travel to only this one seems to need someone stationed at the entrance of the passenger line when there's a HUGE SIGN stating......this line is for First Class and Premiere Elite customers only.
And even the non-major airports that I transit manage to have a First Class or Premiere Elite customer line still don't have people guarding the entrance like FLL does.
I guess all those vacationers don't know how to read after being on a cruise or the beach. The sunshine must too be strong for their feeble brains to function once inside an airport.