No there is no legal defence to this.

You should never need to "slam on the brakes" when traffic lights change. Remembering that amber also means "stop" you should approach them on the basis that they are likely to change at any time and so should be in a position to stop safely if they do.

You could offer the brake problem as mitigation if the matter went to court but you should beware of two things:

You will be treading a fine line between mitigating the offence and admitting driving an unroadworthy vehicle; You would need to have the car examined to establish whether there is a fault or whether the problem was a result of your driving style (which is probably more likely)

Most red light offences are deal with by way of a fixed penalty where no mitigation is considered. If you want to offer mitigation you must decline the fixed penalty and instead allow the matter to go to court. There, even if your mitigation is accepted, the penalty will be considerably higher.

I was taught that a green traffic light ALWAYS means that the next light will be amber so ALWAYS be prepared to stop.

I was taught that a green traffic light ALWAYS means that the next light will be amber so ALWAYS be prepared to stop.

True - but a lot depends on whether you are familiar with the regular cycle of those lights and have seen the previous change. If so, you will have some idea of how many seconds remain on the green phase !

The point of the way I was taught means you don't need to know the regular timing or how much green is left - if it's now green, it WILL turn to amber soon so be prepared to stop.

Follow-on thread now running in Technical:

www.honestjohn.co.uk/forum/post/198601/bmw-320i-f3...r