GOOD LIGHTS IMPORTANT

Press, Volume CVIII, Issue 31729, 12 July 1968, Page 9

GOOD LIGHTS IMPORTANT

'T’O many, night driving is something to avoid, because they feel they cannot see adequately with their own headlights, and because they are unduly affected by the glare from the headlights of others.

This may be the result of bad vision in general and bad night vision in particular, but for almost everyone such eye defects can be corrected. A dislike of night driving may also be caused by badlyadjusted headlights. The efficiency of headlights is of great importance, and it is

important to know if your headlights are in good condition. Look through the lenses and see if the reflectors are bright: sealed beam units cannot tarnish, but lights which use bulbs can easily have their reflectors dulled. It Is also important to keep the glass of the lenses clean: a coating of mud or slush can cut down the amount of light quite drastically. AIMING

Next to cleanliness, correct aim is the important factor. If headlights mounted 2Jft above the ground are given a downward mis-aim of only one degree, for example, their beam centres will meet the ground 140 ft from the car—the distance you would travel in 1.8 seconds at 55 m.p.h.

For this reason, proper headlight aiming is not easy for the inexperienced. Directing the beams at a flat vertical wall with the car standing on level ground at a distance of 10ft, can give fair results.

Legally, you are entitled to have the main beams set parallel to the ground when the car is laden, but the manufacturer will generally set them up to half a degree downward to allow for changes in pitch altitude. You can have your headlights adjusted to make the setting a quarter degree downwards, which will give good results. It is a good idea for a driver to have his headlights tested and adjusted at a garage, then take his car home, position it 10ft from his garage wall, turn his lights on

and make two marks at the points where the beams strike. It is then easy for him to make frequent and fairly accurate headlight checks. Having improved our own seeing distance, it is important to make sure that we do not dazzle oncoming drivers. When two cars with correctly aimed, dipped beams and a lateral separation of 10ft approach each other on a straight, level road, the maximum seeing distance for an object straight ahead is about 130 ft when the cars are roughly 500 ft apart GLARE

But, if the cars remain on main beam, the maximum seeing distance goes down to about 100 ft This demonstrates the value both of prompt and courteous dipping and of proper alignment, since about one degree of upward mis-aim will cause a nominally dipped beam to create four times the accepted glare value. If the headlights are properly adjusted, glare on dipped beam is reduced to an acceptable level.