Welcome to Caltrans District 4
 

District 4 - Alameda, Contra Costa, Marin, Napa, Santa Clara, San Francisco, San Mateo, Solano and Sonoma Counties

The live traffic videos are in a Windows Video format. In order to play them on a Mac you will need to install the Windows Media Components for QuickTime.
http://windows.microsoft.com/en-US/windows/products/windows-media-player/wmcomponents

Click on a red camera icon on the map to view an image