The San Diego Real Time Traffic Map is provided by Caltrans District 11.

If you don't like to get caught in heavy traffic, this website link is one you must have.
It shows current speeds on freeways and major roads, providing real-time traffic information.
If you check this page before starting your drive, you can pick the best route and manage to avoid the bad traffic areas.

Click here to see the San Diego Real Time Traffic Map.