It is common perception that speed breakers can reduce vehicle speeds and prevent accidents. However, speed bumps that do not stick to proper guidelines can cause accidents instead.
Dr. S. Velmurugan, senior principal scientist and former head of the traffic engineering and safety division of the Council of Scientific and Industrial Research (CSIR)-Central Road Research Institute (CRRI), said that only 5% of speed breakers on main roads, and none of those on smaller roads, follow guidelines in Delhi.
How big is the problem of unauthorised speed breakers in the city?
The problem is much bigger than we think it to be. Our research has shown that only about 5% of speed breakers under the Public Works Department (PWD), and none under the municipal corporations, actually follow guidelines of the Indian Road Congress (IRC) and the Unified Traffic and Transportation Infrastructure (Planning and Engineering) Centre. According to the guidelines, the height of the speed bumps should be 0.1 metre with a chord length of 3.7 metre and radius of 17 metre.
How can an unauthorised speed breaker pose a safety concern?
The issue is that even so-called “authorised” speed breakers do not follow norms. Authorities mindlessly construct speed breakers without realising the consequences. According to data available with the Ministry of Road Transport and Highways, as many as 4,700 people died last year because of improper speed breakers on national and State highways, while another 6,000 died because of potholes.
Not just the specifications, but the material used to construct speed breakers is also an issue. According to specifications, bitumen, which lasts longer and allows for smoother landing of vehicles, is to be used. Most speed breakers, however, are made of plastic and PVC, which are more of back-breakers than speed breakers. The nails protruding out of plastic bumps are also a major hazard for two-wheelers and cyclists. Also, this material wears off quickly, especially when loaded trucks keep going over it. Their life span is only five to six months, which turns out to be more costly for the government.
What are the basic specifications to be kept in mind when constructing speed breakers?
It is absolutely necessary to keep engineering needs and markings on speed breakers in mind. Agencies concerned should also see to it that warning signs are in place 45 metres ahead of the speed breaker to ensure that drivers are aware. The number of speed breakers doesn’t really matter, but the ones that are made should be done properly. Ideal locations for construction of speed breakers are junctions, when a minor road enters a colony, and in zones that see high traffic.
Is this a problem unique to Delhi? Can the Capital take lessons from any other Indian city?
While this is a problem in many mega cities, there are places that are getting it right. For example, Chandigarh has been following the guidelines for speed breakers, as a result of which the number of accidents there have come down. In certain parts of Mumbai too, the speed breaker designs are in accordance with the specifications.
