Monday, Apr 18, 2016 at 20:24
Actually Bob, the higher mounted lights present less blinding effect on the approaching driver than do the lower mounted ones. It's all to do with geometry.
With lights mounted at grille height the light beam is aimed almost horizontally along the road and is aimed at infinity and directly into a drivers eyes.
If mounted at a greater height, the lights are aimed at an angle down in order to strike the road at a determined distance ahead and only at the height of an oncoming drivers eyes at one particular distance apart.
This effect is particularly noticeable with low mounted lights, even headlights on low beam, when the road has undulations where a very small change in a vehicles approach angle raises the beam such as to shine directly into the oncoming drivers eyes. I'm sure you would have observed this phenomena.
The diagram below illustrates the effect.
1 = high mounted at normal attitude.
2 = low mounted at normal attitude.
3 = high mounted as vehicle pitches.
4 = low mounted as vehicle pitches.
Note the blinding light beam denoted by a star in 4.
Pitching Lights
FollowupID:
867983