The Salt Lake civic body has finally started road repairs but rather than laying a fresh layer of asphalt, patchwork repairs are being carried out. Residents and engineers of other government agencies are worried about the quality and longevity of the repairs.

Potholes dot all major roads of the township — some in worse shape than others.

The Telegraph had reported on the sorry state of roads in the township on August 7.

The Bidhannagar Municipal Corporation has started the repairs but their engineers are relying on patchwork — a layer of bitumen that is laid over craters — as a quick-fix solution.

Krishna Chakraborty, the chairperson of the Bidhannagar Municipal Corporation’s board of administrators, said: “We will need at least a 15 day-stretch without rain to relay all the stretches. Since there have been showers on most days, we have decided to go ahead with patchwork repairs rather than full-blown repairs,” said Chakraborty.

Of the worst affected stretches, a 1km-stretch that connects Tank Number 9 to the Udayachal tourist lodge is being repaired.

However, on a stretch of Seventh Cross Road that leads from the Karunamoyee intersection to Tank Number 8 and was repaired a few days back, the patches have already started wearing off.

A layer of small stone chips lie on the areas where the patches have worn off, making the stretch dangerous for two-wheelers to negotiate.

A BK Block resident was injured on Saturday afternoon after his bike skidded on the loose stone chips.

“I saw people repairing the stretch on Friday night. I was riding home when a car braked in front of me and I, too, had to hit the brakes. My bike skidded on the loose stone chips that had worn away from the patchwork repairs,” said Vikas Agarwal.

On Saturday, teams of workers were seen pouring buckets of bitumen mix into the potholes.

Another road that will be repaired is a 2km-stretch of Third Avenue that leads to the Wipro intersection from the Karunamoyee intersection.

A Calcutta Metropolitan Development Authority engineer said a road surface laid with mastic asphalt or concrete easily outlasts a surface redone with bitumen. Mastic asphalt could be laid in a short span of time and even in between rains.

But civic authorities keep choosing patchwork over other options.

Around Rs 3.8 crore is required to build a kilometre of mastic asphalt road. Though the cost is many times higher than patchwork repairs, it evens out in the long run because mastic asphalt doesn’t require frequent repairs.

An engineer said: “A concrete road is three times costlier to build compared to bitumen but lasts two decades. The longevity of a bitumen stretch, on the other hand, is a few months. A mastic asphalt road costs double and lasts around five years.”