Enforcing speed restrictions can lower accident rates, say experts

If there is one traffic rule that is uniformly violated by almost every road-user, it would be the limit on vehicular speed that is in place within the city.

Whether the official speed limits are practical is questionable, according to experts. Autorickshaws are not supposed to breach the 25 kmph rule and other vehicles can touch a maximum of 40 kmph. However, the link between over-speeding and fatal accidents is hard to dispute. It is a contributing factor in 60 per cent of all road traffic accidents, as per statistics from the Road Accident Data Management System.

Speed restrictions, if successfully imposed on just arterial roads alone, will drastically bring down accident fatality rates, says A. Veeraraghavan, transportation engineering professor, at IIT-Madras. “A pedestrian hit by a car at 30 kmph has a less than 10 per cent chance of dying, whereas there is an 80 per cent chance of fatality if the vehicle's speed is 50 kmph,” he says.

Apart from improving road safety, speed limits also reduce the environmental impact of road traffic (vehicle noise, vibration, emissions) and reduce fuel use.

But various efforts over the years to introduce speed monitoring on arterial roads have repeatedly failed. The latest attempt by the traffic police through the use of laser speed guns is having some impact, but motorists have already learnt to evade the system. From as many as 4,388 cases that were recorded in April, which was the first full month when the new-generation speed guns were used, the numbers have started dropping. In June, about 3,100 cases of over-speeding were booked.

It is difficult to block a speeding vehicle and book a case, said S. Sivanandan, Additional Deputy Commissioner (Traffic), said. “But there is also some degree of compliance as motorists apply brake on seeing the speed gun,” he added.

Motorists such as Abdul Rahim say that a practical speed limit has to be fixed first. “Breaking systems and engine power have changed drastically ever since the speed limits were set. Also, the police have to start differentiating between over-speeding and rash driving. Laser speed guns are being used to catch and book everyone, even if you are going at only 50 kmph. It is true that over-speeding is rampant, but police seem to be more interested in booking cases than reforming motorists.” Advocating compulsory training courses on defensive driving techniques during the licence issuing process, S. Suresh, director of the Accident Research Centre, says: “The number of unwanted speed-breakers and a lack of lane discipline sometimes encourage aggressive driving.”

K. Giridhar, professor at IIT-Madras, whose team set up a speed monitoring system on the campus, says current enforcement techniques are simply not good enough. “A few cities in Europe have begun testing a speed monitoring system that will allow traffic personnel to restrict fuel injection using sensors in the vehicle's engine. Chennai can start testing motion sensitive cameras that can digitally log every violation. But it all comes down to our road culture. Unless motorists start believing it is being done for everyone's good, things won't improve.”

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