Cabs and GPS

April 6, 2006 4:39 PM

"CabSpotting traces San Francisco's taxi cabs as they travel throughout the Bay Area. The patterns traced by each cab create a living and always-changing map of city life. This map hints at economic, social, and cultural trends that are otherwise invisible."
posted by vacapinta (14 comments total)

That is really cool.
posted by kirkaracha at 4:50 PM on April 6, 2006

GPS tracking is quite awesome. The time-lapse-by-speed movie looks like blood vessels.
posted by blacklite at 4:52 PM on April 6, 2006

This is really fun, and quite typical for the Exploratorium. if you're headed into SFO, I highly recommend going. They're kind of in the northeast corner of SF... they're housed in one of the last buildings left over from the World's Fair that was held there like a hundred years ago.
posted by Malor at 4:56 PM on April 6, 2006

Wow. Amazing.
posted by dobbs at 5:18 PM on April 6, 2006

This is really cool... Now to analyze the hard data and come up with an explanation why there are never any cabs on my street in SF.
posted by davidnin at 5:37 PM on April 6, 2006

That's most excellent. What a fantastic visualization.

I have no idea how these people got their cabs wedged into their spotters, or why.
posted by gleuschk at 5:41 PM on April 6, 2006

Does anyone know why there are some ghost lines that go through blocks, in SOMA for example, as if cabs are traveling through houses?
posted by vacapinta at 6:49 PM on April 6, 2006

I'll bet it's because of the update rate of the GPS. When travelling from a certain street and the point where it takes say, two left turns and gets half way down the block. That's one theory anyways...
posted by davidnin at 6:52 PM on April 6, 2006

Dudes, it's all thanks to the splendid cats at Stamen. We saw a version of this at Design Engaged in November and it blew our socks off even then - but this is nicer.

Some of the artifacts you're experiencing may be due to the fact that this is not quite realtime - seven minutes off, to be precise - although I have trouble imagining just how that would produce e.g. traces through buildings.

On the other hand, one upon a time I was a bike messenger in SF, and I know all too well what those cabbies were capable of. Dooring wasn't the half of it...
posted by adamgreenfield at 8:43 PM on April 6, 2006

Pretty cool. I recall seeing something similar applied to pedestrians walking around Amsterdam - but the execution of this is tighter. The question: does GPS make the cabbies drive any more safely?
posted by quadog at 12:01 AM on April 7, 2006

Nice. I love stuff that shows me what's going on in my old hometown.
posted by greasepig at 8:22 AM on April 7, 2006

This will get more interesting as more Artist Projects are added.
posted by raedyn at 8:23 AM on April 7, 2006

Afroblanco: There are typically about 500-1000 Yellow Cabs riding around SF at any given moment. Only a few are chosen (at random) for the tracker, because showing them all would be a resource drain and a bit of visual data overload. Plus there are a million privacy / surveillance issues raised by this thing, and we wanted to make it difficult to use the visual display to watch specific cabs.

Vacapinta: Each taxi updates its position once per minute, on average. If they're traveling quickly, miss an update, or take sharp turns, it becomes difficult to guess which streets they actually took (as Davidnin points out). The quirks in the data are most visible for eastbound Bay Bridge trips (GPS doesn't work so well on the lower deck) and 101 near the airport, where you see the "bowstring" effect from widely-spaced GPS updates.
posted by migurski at 9:34 AM on April 7, 2006

More cabs? Perhaps - it's just a client-side limitation for the sake of sanity. I could see making scary version that displayed them all, for people with expensive computers. =)
posted by migurski at 12:15 AM on April 8, 2006