I ride a commuter train from the town where I live to the town where I work (and vice versa) a couple of times a week. It’s a two track system with one track reserved for northbound traffic and one for southbound (hopefully). There are 7 stops between where I get on and where I get off so it takes about 40 minutes each way.
In addition to the “milk run” as we affectionately call it, there are also express trains that run from one end of the system to the other without stopping at any stops. As I sit at the station waiting for my train I notice them whiz by and, of course, not stopping at my station.
My question is this. How can they run express trains when they are also running “milk run” trains. Wouldn’t the express trains get backed up behind a train that has to stop at every station? I’ve never seen a way for a train to pass another train (remember there are only two tracks) and I have never been passed by an express train during all of my years commuting. So what’s the deal?