Some people think it's legal to drive through a yellow light if your front tyres are over the stop line before the light changes to red.
But, that's not the rule.
It's only legal to drive through a yellow light if you are unable to stop safely when the light changes.
You see, the yellow light is not an extension of the green light, it's actually the beginning of the red.
So when you approach traffic lights, you should always be prepared to stop in case the light suddenly changes. And you should check your rear view mirror for vehicles travelling close behind. If the light turns yellow, you must stop if it's safe to do so.
However, if you're so close to the intersection when the light changes that you are unable to stop safely, you are legally allowed to drive through the yellow light.
Now, if the light changes to yellow after you've moved into an intersection waiting to turn right, you are also legally allowed to drive through the yellow light to clear the intersection.
Knowing the rules makes travelling through intersections much safer for everyone.