View Single Post
      12-01-2012, 10:57 AM   #3
Flight Lieutenant ≛

Drives: Le Mans blue X1 35i
Join Date: Sep 2012
Location: CT

iTrader: (0)

Originally Posted by danintas View Post
I love the feature ... the only reservation I sometimes have is that they don't go to low beam quick enough, but I haven't been flashed by oncoming cars yet.
Define "not quick enough"?
There are two myths about high-beams I would like to dispel:

1: High-beams should be turned off the moment you see an oncoming car. This is wrong.
They should be turned off when the light cones from the two vehicles start overlapping each other. You cannot blind anyone outside the light cone, and that is the reason to turn them off.
So why not wait even longer?. You want to turn them off while you still have a memory of a fully lit area between the cars. By the time your eyes have adjusted, you should be in the range of the combined low-beams. Turning the high-beams off when the light cones start overlapping is a good compromise.

2: High-beams should not be turned on again until after you have passed an oncoming car. This is wrong.
They should be turned on again about one car length in front of the oncoming car, when there is no longer any risk of your high-beams blinding the oncoming driver.
Failure to turn them back on again means the driver gets several seconds of severely reduced vision after leaving the combined headlight area, before the retina adjusts. Worse, what was right behind the oncoming car, in either lane, is something you didn't see. Needless to say, this is bad.

If anything, I think automated systems like this are too aggressive, yet don't cover situations like an oncoming biker, or a deer.