I would like to build an app that alerts me when road traffic is high or low. Where can I get the raw data?

Question

I'm sitting at work, waiting for traffic to die down. The thought occurred to me. I know when I want to go home, why don't I have an app that watches traffic for me? I also know that there are a lot of smart people on stackoverflow.

Where can I get live traffic data for the san francisco bay area region? The data source should be timely, accurate, and as high resolution as possible. I would like to build an app on top of a service, rather than watch google maps or watch another website. I would prefer that I not have to scrape the data, but I have been know to do this in the past when no other option exists.

Answer 1

If you limit yourself to the San Francisco area, there might be something available from 511.org

Mapquest gets their traffic information from INRIX.

Answer 2

You could check out map quest's beta api http://platform.beta.mapquest.com/traffic/ not sure if it's what you need but it's clean

Answer 3

TraffiCast is the definitive source, I think.