Since the early fall, my commute has involved only IRT trains, and as I’ve written in the past, I find the countdown clocks to make waiting for the next subway a far less stressful experience. As all of my stations now have these clocks, I’ve also started focusing on what the wait times can tell us about subway headways, and I’ve often taken to Twitter to post my observations about train bunching. It seems to happen far more often than we would like.
Take, for instance, off-peak patterns on the 2 and 3. Oftentimes, I’ll see a long wait for a downtown 2 train and a much shorter wait for the 3 train right behind it. The wait times may average out to acceptable headways, but the reality of the situation is far more subtle. I witnessed another strange happening this past Saturday when three downtown 1 trains past within 5 minutes of each other at around 5:15 p.m. Accordingly to the MTA’s schedule, those trains should have been operating with eight minutes of headway rather than 100 seconds.
Some of this bunching may be unavoidable. Perhaps an earlier delay on the 1 line caused Saturday’s bunching, but the 2/3 bunching happens often enough that I wonder if it’s a scheduling issue. The 3 makes just one stop after leaving its terminal before joining up with the downtown 2 that the dispatcher should be able to avoid such bunching. I’ve noticed, however, that the late-night schedule features Manhattan-bound 2 and 4 trains running with similarly mistimed gaps in Brooklyn.
One day, I hope the MTA releases the wealth of data currently being collected by the underlying technology supporting the PA/CIS system. It would provide a glimpse of how trains are running with what spacing as they make their journeys to their ultimate destinations. Perhaps we’d see bunching, and perhaps too we would be able to isolate why bunching happens by discovering which trains are experience high dwell times. For now, though, we just suffer through mystifying and frustrated bunching as the countdown clocks tick down the minutes until the next two trains arrive.