New York City mostly rides transit, Los Angeles loves its cars, and San Francisco has a dedicated population of bike commuters. UC Berkeley planning PhD student Fletcher Foti recently built a brilliant data visualisation that brings these facts to life by animating commuting patterns for the Bay Area, LA and NYC.
Foti uses data taken from the 2010 NYMTC Travel Survey and the 2010 California Household Travel Survey, which are like spatial diaries people fill out with detailed accounts of how they get around. To make people's commutes easy to see, he's chosen to represent a single day. You can scroll from hour to hour or just hit play.
Each dot represents one person, and the larger the dot, the older they are -- that's why you'll see some "kid" dots, usually accompanied by parents. The dots move based on trips taken and are coloured by the last mode of transit used (although the travel doesn't happen in real time). So, if you stay at home all day you'll just be a purple, stationary spot. Or a freelancer.
It's pretty mesmerizing to watch the dots scurry from neighbourhood to neighbourhood like some kind of choreographed urban dance. But for a truly eye-opening experience, Foti allows us to separate the commuters by income. Here, you start to see the reality of how people get to work. The lowest-income brackets are up the earliest, making their journeys mostly via public transportation or walking, and returning home late at night.