Driving After Dark

Press, Volume CVI, Issue 31279, 27 January 1967, Page 9

Driving After Dark

rpHOUGH the volume of 1 traffic is reduced after sunset, the risk of an accident is greater at night than during the day.

Many drivers have difficulties when driving at night. They have difficulty in judi ging distance or in seeing properly when meeting oncoming traffic, and find these problems are accentuated on ’ a wet night. This is to be expected, as a brief consideration of nightvision will show. In the retina of the eye, cones react to the sensation of colour and rods respond to light. As light decreases, all colours tend to become greys. The cones then cease to function, and rod (night) vision operates. As the light decreases, the sensitivity to light is in creased. Adjustment to the dark, as in the darkroom or theatre, increases the concentration in the rods of a purple photochemical that is referred to as “visual purple.” The visual purple is essential to perception in the dark, but when exposed to bright light it bleaches. When the bright light is removed the purple is restored, but only slowly. It takes some time for the visual purple to be suffici(ently regained to deal with dimness.

This is why dazzling headlights at night are dangerous. They not only blind the driver approaching them, but, after passing, it takes some time to restore visual purple for him to see clearly. This simple explanation of night sight shows the prudence of basic rules of safe night driving. Always dip your headlights when another car is approaching, or when closely following another vehicle. Bright light from behind can dazzle the driver in front when reflected from his rear vision mirror.

Make sure your headlights are always properly adjusted, that they do not rise above the horizontal on full beam, especially when your car is abnormally tail-loaded. If you are involved in any sort of bump that may have upset the headlamp level, have your garage make a check at once. Do not wait for the expiry of your warrant of fitness before you do it. Avoid looking directly at the headlights of an approving car. Concentrate on watching the left of the road. Slow down when your eyesight is affected by changing light, and stop if badly dazzled. Driving blind is dangerous

Never outdrive the range of your headlights. You must be able to stop within half the visible distance ahead. “Slow down at sundown” -is still a useful axiom.

Other points to remember: Keep your windsceeen clean. A dirty windscreen reflects

THE DUNLOP company of Britain supplied Monte Carlo rally competitors with 2000 radial-ply tyres.

A NEW TYPE of tyre stud said to give more stability and adhesion on ice was used by competitors in the Monte Carlo rally.

light. In wet weather one of the several special cleaning and water-clearing solutions will be a great help. Do not wear dark or tinted glasses when driving after sundown. Avoid use of interior lights, except dim instrument lighting. Keep headlight and taillight lenses clean. Dirt and

dust reduce the light output. Avoid night driving when tired, because night vision and concentration are impaired. Finally, if you do become sleepy, it is better to stop and have a rest or get some fresh air into your lungs. The moment of drowsiness or inattention could be your last.