Dwell times- why your train is slow

In theory, commuter trains can go up to 90mph, but most of the time they stop every few minutes and never reach this speed. The amount of time a train spends at each stop isn’t much, but it adds up.

This is called “dwell time,” the total time that the train stops, or “dwells” in at a station.

Here’s some data sent to me by a friend. He recorded how long his train spent at each stop, from Upper Montclair to Newark.  The timer starts when the train comes to a full stop, and ends when the train begins moving again.

Screen Shot 2015-09-01 at 11.50.21 AMAccording to the Montclair Boonton-Line schedule, The trip from Upper Montclair to Newark Broad Street takes anywhere from 24 to 27 minutes. If we subtract the dwell time for Upper Montclair and Newark, The train is not moving at all for 9 minutes 33 seconds inbound and 8 minutes 45 seconds outbound. That’s anywhere from 32% to 37% of the scheduled trip time from Upper Montclair to Newark.

Now granted, the data here is from rush hour trains and doesn’t include the section of the line between New York and Newark with fewer stops, so it’s not entirely representative.

Here’s the same information in graphical format:

Screen Shot 2015-09-01 at 12.08.02 PM

Screen Shot 2015-09-01 at 12.08.08 PM

You’ll notice that the stops that took the least time were Upper Montclair, Bay Street, and Watsessing. Watsessing and Upper Montclair took less time because they have lower ridership.  In Fall 2013 (the most recent available stats), Watsessing has 223 daily boardings and Upper Montclair had 519.

Bay Street, on the other hand, had 1,166 boardings, making it the busiest stop on the line.  This is interesting.  Bay Street is the busiest stop on the line yet it has one of the lowest dwell times.

The reason is simple.  Bay Street has high level platforms, which make the boarding process faster. Conductors can open the center doors as well as the end doors.  Passengers also don’t have to climb up or down stairs, which can slow things down.

Let’s compare Bay Street to Walnut Street and Glen Ridge, two stations with similar ridership (1,025 and 1,098 boardings a day, respectively) and conventional low level platforms.

In the inbound direction, Bay Street averages 1 minute 16 seconds,  while Walnut Street takes 1 minute 30 seconds and Glen Ridge 2 minutes 6 seconds. Outbound, stopping at Bay street takes an average of 1 minute 11 seconds, while Glen Ridge takes 1 minute 17 and Walnut Street takes 2 minutes 6 seconds.  In many cases, the high level platform allows the train to enter and leave the station more than 50% faster.

If the entire line was converted to high-level platforms, trains would run faster.  At approximately 30-45 seconds saved at each stop, the trip from Upper Montclair to Newark would take about 20 minutes, not 25.  This would be, of course, a huge capital investment.  But it’s also something that the LIRR and Metro-North have already done-  decades ago.

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