CA AB2128

Requires Department of Transportation or local authority to use the next higher 5 mph increment of 85th-percentile speed to determine minimum yellow light change intervals when rounding down speed limits to the lower 5 mph increment.

Prohibits drivers facing a steady circular red signal from proceeding straight through the intersection or turning left (except left turns from one-way to one-way streets) until an indication to proceed is shown; allows right turns and one-way left turns except where prohibited by sign.

Requires local governmental agencies operating automated traffic enforcement systems to extend yellow light intervals by one second beyond the minimum intervals designated in the California Manual on Uniform Traffic Control Devices (MUTCD).

Mandates dismissal of citations issued by law enforcement if the local governmental agency has not established yellow light change intervals in compliance with the one-second extension requirement.