Article explains what is behind traffic jams that occur for no apparent reason, such as an accident or construction.

Look up real time traffic reports for cities around the United States including the San Francisco Bay area and New York City.

Guide offers links to national traffic and road condition reports and to Internet-based traffic schools and traffic-ticket payment systems.

Provides real-time road traffic reports for many regions throughout California, including Los Angeles, San Francisco, and San Diego. Also find freeway-speed maps.

Find traffic updates and public transportation reports for major US cities on this commuter resource. Search metropolitan areas by freeway.

Freeway travelers can access travel information, traffic alerts and accident reports for key travel routes in several major US cities.

Get weather forecasts for major US highways. Also offers global weather outlooks, radar images, storm info and a weather Q and A.