Green Means Go

The more closely you follow the car in front of you after a light turns green, the more cars get through by the time it turns red. This makes more of a difference than people seem to realize. Green means go. The simplest rule of driving is the hardest for people to understand.

If all drivers were rational actors, each driver would go as soon as the light turned green, because it would be safe to assume that everyone else would do the same. Why wouldn't they? Cars generally come with something called brakes. You can use the brakes to stop your car if someone in front of you doesn't go when the light turns green for some reason (medical emergency? abducted by aliens? spontaneous combustion?)

But it's a tragedy of the commons. In reality every driver can reasonably assume that the other drivers at a red light will be watching Instagram Reels. If you're the fifth car in line, there's no point in trying to go when the light turns green. You will just have to wait for four strangers to remember, one at a time, that they are driving a car.