6.1.6 Night Driving

"A frequent cause of accidents at nights is the glare caused by oncoming vehicles which momentarily blinds the driver's vision. It takes three to eight seconds for a person with good eyesight to recover from the glare and during this time the vehicle will have covered a long distance in utter darkness and it will be sheer luck if it escapes an accident. A glare recovery test should be carried out to gauge the applicant's ability in this direction, followed by tests pertaining t color and night blindness."

"This is one of the common failings of our drivers in night driving, specially on dark or badly lit roads that we generally have in rural areas and also along many of the roads in our cities and towns. Driving courtesy imposes a special responsibility on the driver, that the oncoming driver is not handicapped by the dazzle of headlights. To avoid this, it is imperative that as the vehicles approach from opposite directions, the main beams should be switched OFF and the dipped beams used instead, so that the two vehicles can pass each other safely. Country to the above requirement, many of our heavy vehicle drivers are given to the practice of blinding oncoming vehicles drivers by using both the main and dipped beams of their headlights simultaneously, to gain on advantage over the oncoming driver."

While the above refers to the culture of road users, the road situation itself is disheartening in our country. The highways in developed countries are mostly of 6 lanes divided type, meeting very good geometrical requirements so as to minimize glare whereas in India only 1.48% of the total length of National Highway is of the standard multi-lane type (Source: Basic Road Statistics of India, Ministry of Surface Transport Government of India).

The observations of the study group on road safety (Constituted by Government of India vide Resolution No.19 (14) 68, June 3, 1969) regarding the conditions of our national highways are:

"The Indian roads are all essentially very narrow, tortuous in their alignment and suffer from many inadequacies, vis-à-vis the present day motor traffic which has registered a phenomenal increase during the post-Independence period. The other conditions of the roads like poor shoulders, narrow culverts and bridges, sharp and numerous curves and steep gradients which limit the sight distance, numerous low level causeways and submersible bridges are perennial hazards. All the above tell on the nerves of the driver, causing fatigue and leading to errors and misjudgment while driving.

All the above indicate the importance of dipping of headlights in a country like India, so as to avoid the problem of glare which impairs the visibility which is vital for safe driving in a meeting situation during the night. This leads to the conclusion that an Auto Dipping Device can go a long way towards safety enhancement.

The human eye, one of the most complex organs and the greatest gift of nature, is equipped with a variety of adaptation abilities. However, it is incapacitated by glare. The human eye's inability to refuse glare sources in the normal visual field (the sun does not fall in the normal visual field) during the long evolution process might be because nature was unaware of man's potential to create disabling sources-the most serious of which is vehicle headlight glare. The visibility of an object is determined by many factors apart from background luminance. Mere reduction of background luminance by an auto dipper in a particular situation need not necessarily result in clear perception of the objects on the road through visual information. The physical dimensions of the object, the luminance reaching the object, it's reflectance factor, its colour contrast, its time constancy, its movement in space, etc. determine the nature and quantum of visual information available. The actual perception is dependent on the physical condition and the perception method of the viewer. The headlight systems of the vehicle, including the number and type of lamps, their alignment and their efficiency, all play a vital role in influencing the visibility of objects on the road.

An auto dipper could play a crucial role in shifting the headlights from driving beam to meeting beam and vice versa. This will improve visibility by minimizing glare, a major cause of momentary loss of vision. The realization of the ultimate goal of total road safety through creating ideal visibility conditions is dependent on efforts in all other related areas mentioned above.