While it may look like one of those nuclear blast-radius maps, with its array of alarming red blobs over major cities, this model carries a much less threatening, even heartening message: In the past decade, urban America has fallen in love with public transportation, with nearly universal ridership increases on buses, light rail and other forms of shared transit.
The visualization is part of an ongoing series called "Transit Patterns" made by Schema Design, a Seattle creative firm that dabbles in mapping things like rush-hour commuters and grocery shoppers. Schema has taken ridership info spanning 2002 to 2012 from the National Transit Database and overlaid it on a base map of stations and terminals to create this pulsing wonder, which if you download the app version can be tweaked to show patterns by time of year or mode of transport.
You'll notice that over time the blobs swell larger and larger, meaning more people are riding public transit in that city. That reflects a growing trend in ridership that saw more than 10 billion passenger trips in 2012 and record-breaking numbers on many transit systems, despite the dampening effects of Superstorm Sandy. There are no doubt many reasons behind this surge; one industry expert believes its likely being driven by changing demographics and high gas prices, saying that switching from a car to public transit can save a person $10,000 or more a year.
Schema founder Christian Marc Schmidt, a former interaction designer at Microsoft, recently took the time to chat about some of the things that stand out in this visualization. "The biggest thing really is the general increase" in ridership, he says. "With light-rail transit, we definitely found it appears to be increasing overall, and with heavy rail there's a little more consistency."
A few notes: "Heavy rail" means the kind of subway lines found in cities like New York and San Francisco. The "streetcar" category includes cable cars, raised tramways and monorails, and trolleys fall under the umbrella of "bus." This map shows only transit within cities – Amtrak and other intercity movers are left out. And don't get excited about that big jump in ridership from 2011 and 2012, as it's mostly due to a change in reporting methods.
Here are some of Schmidt's takeaways:
• "Ridership across all four transit categories grows steadily from 2002 to 2012.
• Ridership in rail transit increases steadily, in particular in New York where there is a dramatic increase by 2012 – almost a 150 percent increase from the 2002 numbers.
• Ridership in bus transit remains steady with modest gains in cities like Seattle and Miami, though it actually falls in a few of the nation's largest cities including New York City, Los Angeles and San Francisco.
• There are only very few cities with rail transit across the U.S., in particular the category we call "streetcar." Bus transit is more pervasive, but is concentrated on the East and West coasts, while remaining relatively sparse in the Midwest.
• By selecting "Trips Per Person" we can see the cities across the country that have the most public transit ridership relative to their population. Here we see a high concentration in public-transit ridership in the coastal areas, while the Midwest and Southwest rank much lower. Overall, buses have the highest per capita ridership, followed by heavy rail (i.e., subways), light rail and streetcars.
• It is noteworthy that many cities in the Midwest like Kansas City, Omaha and Albuquerque have below one trip per person on average per month. Contrast that with the two cities that have the highest trips per person, San Francisco and New York, for which the average number of trips per person ranges between 10 and 18 for December 2012, respectively. In New York, over half of the trips per person are due to heavy rail (subway) – filtering out heavy rail reduces the numbers from 18 trips per person to around 6.5.
• In many smaller cities there is a dramatic increase of light-rail ridership per person. We can see this in Salt Lake City, where light-rail trips per person doubled from 2002 to 2012. Other cities that have seen large growth in light-rail ridership include Seattle and Denver.
• There are a few interesting outliers in ridership per capita. While most cities see increasing trips per person, San Francisco and New Orleans are noteworthy exceptions. New Orleans starts in the top three of ridership per person, but falls dramatically after August 2005 due to Katrina. San Francisco has seen a steady decrease in overall ridership per person in the bus and streetcar categories, though light and heavy rail are growing."