While DFW is huge and probably has flights arriving at all times, there are obvious lulls. But once you see a few drivers head out from the queuing area, you know there is a good chance you will soon get a ping.
Terminal E sucks balls. Cannot wait till they finish their construction. It's a mess, though one of our busiest areas for pickups.
I have also noticed that going from terminal B staging area to Terminal A, is currently blocked due to construction, which means your pax will watch you drive away from them (such as towards the gates) so that you can take the detour (U-Turn) to get back to terminal A. I have had a pax cancel as I did that (whether that was his reason or not, who knows), so I would advise calling them prior to give a heads up.
Terminal D is nicely laid, though sometimes less clear on where to meet the pax as they do not have clear entry gates etc... just ranges. It appears we use the left lane pickup (the side designated for everyone else and limos) while taxis and shuttles use the right lane.
At the other terminals, yellow cones appear to mean designated taxi pickup areas, while blue cones and a few signs, seem to designate pre-arranged limo (which is the category we apparently fall into).
In some ways, Love Field seems more organized, though I have yet to see it nearly as swamped around the Ground Transportation / Transportation Network area, as they get at some of the DFW terminals.
Too many parked cars along the curbs of each terminal when it is busy at DFW.