These are images from the real-time traffic cameras operated by SDOT on 15th Ave NW between Leary and Holman Road. SDOT has a more comprehensive Traveler’s Information Map where these and other SDOT camera images are available. Washington State Dept of Transportation maintains a traffic information map with camera images for I5 and SR99 (among others) in the Seattle area.
To update the images, click the refresh button in your browser. New images are available every few minutes.