In our legal system, it's "innocent until proven guilty" but on our roadways, you should drive with the opposite presumption. While you're driving, assume that other drivers are going to do the most dangerous, most unpredictable thing.
If you're approaching an intersection and have a green light, assume that the other cars AREN'T going to stop. Rather than zooming through the intersection blindly, slow down slightly (not too much because you don't want to be a danger to the drivers in cars behind you!) and check the cross streets. Have the cars stopped? What about further down each cross street: Are those cars slowing down?
And this doesn't just apply to intersections. It applies to drivers everywhere: The car in front of you, the car behind you, the cars approaching, in parking lots, on highways, and more. Assume the worst and you'll start predicting the unpredictable behavior of other drivers... and you'll drive safer because of it.
