Are pulsing brake lights legal?

The men reasoned that the strobing effect would better warn drivers behind them of the braking. The good officer dug into the Vehicle Code and learned that, yes, in California the devices are legal – so long as the brake lights flash no more than four times within four seconds.

How does the pulse brake light work?

The safety device is installed on a vehicle’s existing third brake light. When your driver steps on the pedal, the third brake light pulses four times in under two seconds for increased visibility in braking, improving the reaction time of surrounding drivers up to 50%.