Major cities probably all have them, but the US has a large number of smaller non-hub airports that feed into the hubs, and I know that at least some don't have

Major cities probably all have them, but the US has a large number of smaller non-hub airports that feed into the hubs, and I know that at least some don't have them. In fact, I've only experienced them once, at SFO. When traveling TRI -> ATL -> LHR and returning via Detroit this summer, I experienced none. So if you don't mind spending an extra $150 per trip and running from the far ends of the airport where the feeders dock, you can still avoid the them, at least for now..