The statutory framework
Automated enforcement is authorized by VC 21455.5 and governed by strict notice and evidence rules: warning signs at intersection approaches, a 30-day public-education period when cameras are introduced, and specific hearsay-exception foundations for the photos and video.
Common vulnerabilities
Many red-light camera cases fail when: (1) the photograph does not clearly identify the driver, (2) the "Notice to Appear" was never personally served or never properly mailed under VC 40518, (3) the yellow-light interval does not meet the Caltrans minimum for the posted speed limit, or (4) the system’s log/calibration certificate is missing from the officer’s declaration.
The identification problem
California prosecutors must prove you were the driver. If the camera image does not show your face clearly, a TBWD stating "the photograph does not clearly depict the driver" is often sufficient to dismiss.