[Thymeclock]

Originally Posted by Kodak

Heh, the horn seems like the most immediate response.

That is the legitimate purpose of using the horn - to warn of impending danger.

My only thought is that drivers that are first car at a light may interpret a horn to mean "hurry - you're wasting my time!" - resulting in a quick acceleration...backwards. On the other hand, it may have the desired effect of bringing their attention to the actual problem.

That is why I suggested that you would need to wait until you see some motion backwards, towards you.

I took this one step further and asked myself a related question.

Which would be better in this situation: backing up as far away from the car as possible - giving the driver more reaction time to stop (but also allowing them to be at a greater speed in the case of a collision), OR driving right up to their bumper - practically tapping it - to eliminate the chance of them speeding into you, but increasing the chance of a little bumper to bumper contact?

Backing up is fine as long as there is no one behind you. But if there is, you are merely repeating the situation created by the car in front of you. Driving right up to their bumper is a no-no. The law does not require you to take extraordinary measures to prevent a collision. Often it is better to let the other party crash into you if they are totally at fault. If you contribute to the collision in any way you will contribute to the comparative negligence. (click here)