It depends on where you live. But the rule of thumb I was taught is that if you can see another driver's car in front of you, you should dim your headlights. That usually means to keep your brights off whenever you can see oncoming traffic or whenever you are behind another car that you can see.
500 feet if the vehicle is coming to you, 300 feet if you are following it.
Within 500 feet of oncoming traffic.
100
i believe when I took my test to get my permit it was 300 feet.
200 feet
You must return to the right side of the road before coming within 200 feet of any vehicle coming from the opposite direction.
When you come within 100 feet of an intersection or a railroad crossing, passing another vehicle is permitted.
100 feet
100 feet
500ft if it's oncoming. 350ft if you're coming up behind someone.
300 feet !
500 feet