Wondering if any of you would know why some airports/terminals have such lines ... and why other do not ....
I can't figure it out .... it doesn't appear to be related to size, being a hub for an airline or anything that is obvious ....
Focusing on UA terminals: SFO yes, ORD yes, RDU (?) yes (!), MIA yes, HNL yes but somehow IAD NO ???? (this is even more weird given that there are loads of diplomats, and senior gov folks with their dedicated parking spots that are flying out of IAD !)

Who has the initiative to create such lines :
-TSA ?
-Airport authority ?
-Airlines ?

Pierre