# Transit Flow

By [Brandon Donnelly](https://brandondonnelly.com) · 2017-03-05

bart, bay-area, bay-area-rapid-transit-network, network, oakland, ray-luong, san-francisco, san-francisco-bay-area, trains, transbay-tube, transit, uncategorized, visualization

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This is a map of the Bay Area Rapid Transit network:

![](https://storage.googleapis.com/papyrus_images/53d276f4225a1eb7ab52c380664aca73.jpg)

And this is an elegant visualization by [Ray Luong](http://rayluong.com/transitflow) of ridership levels over the course of one day: February 4, 2016. If you can’t see the embedded video below, [click here](https://rayyayyar.github.io/bart-flow/).

\[youtube https://www.youtube.com/watch?v=owGgbAS7Wq8?rel=0&w=560&h=315\]

Note how the lines speed up as they go through the [Transbay Tube](https://en.wikipedia.org/wiki/Transbay_Tube) connecting San Francisco and Oakland. That’s actually what happens. Within the 10 km-long tube, the trains reach ~130 km/h, which is more than twice as fast as the average speed throughout the rest of the network.

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*Originally published on [Brandon Donnelly](https://brandondonnelly.com/transit-flow)*