Layovers Tutorial

Hi, I saw a tutorial on how to do these for airports but can't recall where. Does anyone know of a good tutorial on how do this? I have Simmflyers Chicago scenery and the afcad file has airport packed but the airlines are using one runway to depart and this is causing major backlog of airplanes waiting. This is fun to sit and watch but I'd also like to open more runways and really get things humming. Thank yu, S.