> Headlights mostly light up what’s ahead of you, not what’s on your side. Good headlamps should have a uniform and widely distributed beam pattern which shou

> Headlights mostly light up what’s ahead of you, not what’s on your side. Good headlamps should have a uniform and widely distributed beam pattern which should be able to light up at least the lane of traffic you're in, as well as the shoulder and several lanes to the left.