Call General Motors

Better yet U.S. Dept. of Transportation. I know they are the source of the information. Years age I researched legal headlight aiming patterns to try to come up with a wall chart or grid. They have the info.

This was in an effort to produce a chart for sale through parts stores. What I finally realized was that few people, except state inspectors, seem to care where their headlights are aimed as long as they can see well, and if they can't they just adjust adjust them to their liking without regard for other drivers. And then there are the new high intensity lights that, even if they are adjusted right, blind the oncoming driver.

yrs ago, I too used a chart to adj the headlights, most car manuals had one so that ya could adj, but that was back in the 70's

Yep! We seemed to do things better (correctly) back then - '70s.Good Old Days...

I too have toyed with this idea. Less so than it seems that you have, but if we both have, then perhaps the market is stronger than we independently assumed.

Go teach those bas%^^ds to check their lights!

I have decided that it is more effective to use the mirror motors of my own car to reflect back. It's great fun ya know!

cr3

One of the problems I found was that it requires that the vehicle be 25' from a wall on a perfectly (pretty much) level surface. How many people have that. Most driveways are slanted for run-off.

The last time I did it, I happened to be in a parking garage at three in the morning (I was a bartender at the time. I don't just do this stuff in the middle of the night...usually). It took a while just to back up very perpendicular to the wall. Then I taped string to the center of each headlight and took it to the wall (level) and tried to get it perpendicular to the wall and marked the spot with tape. Then it was just a matter of measuring a few inches over and down for each light according to the LAW and placing a tape marker there. I even placed tape on the floor at each tire so I could use it in the future (this was a little used area of the garage). The gate keeper thought I was nuts, which probably isn't far off. The tape marks were still there three years later (does tape qualify for graffiti). That was thirty years ago. That's the Hartford Connecticut Civic Center parking lot on the corner of Church and Main Streets, level two east as I recall. Leave the tape in place, please. I'm planning a trip.

Try driving just left of the car in front of you and get your headlight to shine in thier side mirror. Great at long stop lights and traffic backups. Aiming the side mirror to reflect their headlight is not as effective. Square law and all that. Ah, the Scientific Method.

Yes yes. I used to travel a great deal and prior to any trips I would pull up to a glass front building and check signal and brake lights in the reflection. As for head lights. I was shown where they should point buy my stepdad who drove in Nam. It is just common sense for me. If the cars in front of me are flashing they are too high. If I pull up behind and they are adjusting mirrors, or I can see that I am binding them they are too high.

The car does not need to be on a flat surface. If the incline or decline is close to constant then the distance above horizon at say 20-25' is the same measured from the ground up (trigonometry).

It really comes down to people giving a damn, and taking notice to the world around them and how they in turn affect the folks around them.

cr3

Try...http://search.google.dot.gov/NHTSA/NHTSASearchProcess.asp?ie=&site=DOT_Pages&output=xml_no_dtd&client=DOT_Pages&lr=&proxystylesheet=DOT_Pages&oe=&nhtsa_only=1&q=headlight+glare

There are Federal Motor Vehicle Requirements (for exterior lighting it is MVSS 108) for beam patterns (location and intensity). Not all owners manuals have specifics for aiming headlamps but they are all required to be aimed vertically (not horizontally in North America).

How much research does a wood fence or brick wall and some evergreen trees need?

Depending on the proximity of the fence or wall to the location of the vehicle it would have an impact.....and having gone through the court of public opinion during municipal reviews in the past......it's always nice to have a bit of research to be able to refer to.

Hi TAB: I know european regulations that give provisions to this matter, specially for "crossing beam". I post here an image as example how they solve the problem of not glare other vehicles.

Regards.

Gabriel