While driving home in his new Maruti Zen one afternoon in January, Kiran Patil, 19, a Belgaum, Karnataka, student was also busy on his cellphone. A truck suddenly shot towards Kiran, collided with his car and killed the teenager.

On an evening in September last year, a Pune motorcyclist was using his cellphone when he rammed into Monica Bhat’s bicycle. Monica, an undergraduate at the city’s Fergusson College, suffered head injuries. She went into a coma and died within days.

Cellphones, marvels of technology, are used to report emergencies, locate directions, call home, message friends, do business from the beach or golf course—life without them is now difficult to imagine. But cellphones have been proven downright deadly if employed while driving a vehicle or walking down the street.

 The mindless mistakes that cellphone users make are many and varied. It may be as trivial as getting off the wrong floor from a lift; or as serious as fatally falling down a flight of stairs. And most common of all: people getting knocked down by all kinds of vehicles. In June 2005, Prabir Kumar De, a Kolkata make-up artist, was at a morning photo shoot near a railway track when he answered a cellphone call. As De spoke, he moved closer and closer to the tracks. He couldn’t have heard the sound of an approaching train or even its horn, for he kept on walking and talking until the train hit—and killed him on the spot.

Why the Danger?

Your sense of hearing is almost completely consumed by the phone you’re using, and your brain tends to filter out ambient sounds. Unlike a car’s radio, for instance, the phone requires a two-way conversation. So your brain has to absorb the information and work simultaneously to provide responses, making it hard for it to process information that’s not related to your phone conversation.

A cellphone-using motorist is also likely to look at but not see a vehicle, or a pedestrian, crossing his path. He may hear but not pay attention to a horn, or the sound of another vehicle, as he would if he were just driving. By the time he becomes aware, it may be a split-second too late. Likewise, a cellphone-using pedestrian, too, exposes himself to the dangers around him.

In a report on the safety implications of “using mobiles while mobile,” the Delhi-based Central Road Research Institute (CRRI) analyzes the many skills required by a motorist: Watching the road, checking the rear- and side-view mirrors, and keeping an eye on dashboard gauges are some tasks that require visual and cognitive skills. Sharp auditory senses are also required to listen for other vehicles, horns, policemen’s whistles, emergency-sirens, and other sounds that may require the driver to alter his course. Steering the vehicle, controlling the pedals,