Toss a handful of multicolored caterpillars on a dinner plate, and you’ll get something resembling this nifty, almost abstract-art model of Bay Area BART traffic.
Local product designer Ray Luong made “Transit Flow” with d3 and BART data to show how ridership ebbs and flows in a typical work day (in this case, February 4, 2016). The action starts almost imperceptibly before dawn, with watery-hued traces scooting around a beige plane. By the morning rush these have been replaced with swollen, crawling tubes, the fatter girths of which indicate heavier passenger loads. The geographical mid-point where they speed up represents underwater passage through the Transbay Tube, home to a sonic experience one rider compares to a “steel banshee gargling a chainsaw.”
“I’ve been in the Bay Area for five-plus years now and have always been interested in the people and stories that make up the urban landscape,” says Luong. “After seeing the climb in BART ridership over the past few years, I thought it would be an interesting narrative to visualize the pulse of people coming in and out of the city. For me, it’s fun watching the city wake up around 6 a.m., then imagining thousands of people going home after work.”
For simplicity’s sake, the simulation first only shows trains heading from the East Bay into San Francisco. Around noon, though, controls appear in the lower left where you can switch to outbound traffic as well as speed up the action. Luong says that in the future he’d like to “build out some controls to select different days (perhaps a range of days) to see how the patterns might change on a weekend, holiday, or special event.”
H/t Transit Maps