Yahoo! is shutting down the Traffic Rest API and the Traffic RSS Feed. If you have any concerns or questions, please don't hesitate to contact us in General Discussion at YDN forum.
The Traffic Web Services from Yahoo! enable you to access real-time traffic alerts information for a given location. Build applications that use this dynamic traffic alert data to help you plan optimal routes and keep on top of your commute. Traffic data also makes a great addition to a mashup with Yahoo! Maps.
Yahoo! offers two interfaces for accessing traffic alerts data: a REST API and a dynamic RSS feed.
Use the REST API to build a traffic web services query with information about location (city, state, zip, latitude-longitude), the search radius in miles, and the severity of the alerts you're interested in. You can also get a map image for the visual location of each alert you get back.
You can also access our traffic web services through a dynamic RSS feed. Use the same parameters from the REST API to build an RSS feed request, and then subscribe to that feed in My Yahoo! or your favorite feed aggregator. Or, use that RSS data in a mashup with Yahoo! Maps to build up-to-the-minute location-based applications.
The Traffic Web Services are discussed on the yws-maps mailing list.
Traffic Web Services typically have rate limits. See the terms of service attached to each API for the specific rate limit that applies. See information on rate limiting.