With eerie regularity, New York City has experienced a late summer/early fall freakish storm for each of the last three years. In September of 2010, there was the microburst paired with two tornadoes that touched down in Brooklyn and Queens. Then, in August of 2011 came Hurricane Irene. And, of course, last October, Superstorm Sandy inundated the city, paralyzing whole parts of the region for days.
The below data visualization, created by Eric Schles and Thomas Levine, tracks the impact each of those storms had on the city's transit system. The little black lines, which appear as squiggles on an earthquake seismogram, illustrate turnstile entries into New York's subway system from every entrance in the network (one continuous line represents one entry point). The regular waves of passenger traffic capture the flow of week days (peaks) and weekends (troughs).
Then, in the center of each 40-day timeline, a storm hits. The microburst struck on a Friday night and clearly had little impact on transit ridership. But the New York Metropolitan Transportation Authority shut down subway service as Irene and Sandy approached the following two years. The system's resilience – how quickly ridership returned to normal – can be seen in this data:
Sandy clearly caused the most disruption, with parts of the subway system coming back online over the following week (those few horizontal lines in the midst of the storm show times when data points were missing, although the MTA did send workers into the subway while service was suspended). We've seen other compelling visualizations of Sandy's impact on the city's commuting patterns. This one neatly shows the rhythm of a city in perpetual motion – and what happens when it comes to a standstill.
"We wanted it to be really gritty and sort of raw," Schles says. "There are a number of things we could have done that would be higher level and really pretty. But we just felt like we needed to do the realness of the events justice. So something really stark, in black and white, seemed appropriate."