You've been standing on the subway platform for 15 minutes now and the train has yet to arrive. There are at least 40 others huffing and puffing, looking down the track for an inkling of light to indicate a train is approaching.
So what the heck is happening?
A new video produced by New York City's Metropolitan
Here's the quick rundown:
Subway lines are programmed so that every train is spaced evenly from station to station. This, in a perfect world, means that each station's wait time is generally the same.
YouTube
YouTube
But if an event happens that causes one train to remain at the station - even if it's just for a few seconds - an uneven gap between trains occurs.
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YouTube
This gap only gets bigger as the trains that aren't stopped at the front continue running on schedule and those behind the stopped train remain delayed.
This causes the stations in the middle to experience a prolonged wait time.
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YouTube
The MTA attempts to fix this by holding back one of the non-delayed trains. This creates two smaller service gaps instead of one huge one.
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YouTube
But even with these measures to mitigate delay time, just a few seconds can cause a huge chain reaction, leaving passengers tapping their toes and waiting for the next train.
This may not seem like rocket science, but seeing train flow from this perspective helps explain why delays occur so often.
And, it's even cooler and more engaging to see it through fun 8-bit animation.
You can watch the entire video below.