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If you have ever been blinded on the road by an intense bluish white light from an oncoming vehicle, you have experienced the phenomenon called headlight glare.

Headlamps are supposed to provide sufficient illumination of the road ahead to facilitate safety at night. Experts say that the headlamps, however, are proving one of the causes for fatal accidents as design standards and user discipline have been completely overlooked.

Nearly half of all traffic-related fatalities occur at night, despite less than 25 per cent of daytime traffic plying on the road between 10 p.m. and 6 a.m., says A.Veeraraghavan, Transportation Engineering Professor at IIT-Madras. “Next to over-speeding, headlight glare is one of the primary causes for accidents. Apart from temporarily blinding a motorist, repeated exposure to glare can also result in eye fatigue which leads to an accident.”

Every vehicle's headlamp has two modes of operation — High beam or driving beam and low beam or meeting beam. Low beam directs most of the light downward to provide safe forward visibility without excessive glare or back-dazzle.

“The glare from the high-beam light forms a veil of luminance which reduces contrast resulting in poor visibility,” says P. Kanthamani, a neuro-ophthalmologist. “The problem is amplified by pitch dark roads, lack of medians in many places and inconspicuous speed breakers.”

“Road users are not bothered to use dimmed lights,” says J. Krishnamoorthy, Joint Director, Institute of Road Transport. “It is an attitudinal problem if motorists do not dim their headlights even on roads that have proper illumination.”

While the Central Motor Vehicles Act prescribes that headlamps should not exceed 80 watts of power, he says that most goods vehicles use focus beams that exceed 100 watts. “Though only two headlamps are allowed even on heavy vehicles, many use four or six lamps. Drivers must periodically undergo medical checks to test for night blindness. Right of way must not come at the cost of human lives.”

He adds that on arterial roads, the median must have at least two-meter-high vegetation to ensure reduction of glare from oncoming vehicles.

Rohit Baluja, president, Institute of Road Traffic Education, says that there are no systems in place to enforce rules. “There are no data on the number of motorists booked at night for using dazzling lights. Headlight condition is also not taken as part of vehicle fitness.”

He adds that all major roads must be provided with reflective boundary markings, luminescent guard posts near sharp curves and reflective traffic control devices to ensure that the distance of illumination required for safe driving is also reduced.

Admitting that adequate illumination was a problem, Additional Commissioner of Police (Traffic) M. Ravi said that the department has written to agencies concerned to provide better street-lighting on various roads, including certain stretches of Arcot Road and Rajiv Gandhi Salai. “Ideally, the licensing process must be the stage where awareness about glare is imparted to motorists,” he adds.

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