The perilous stretch of EM Bypass between Science City and the Briji Metro station in Garia was repaired between Monday night and Wednesday afternoon. However, engineers stated that it remains to be observed how long the repairs will last during the rainy season.

The patch repairs were carried out to cover potholes that were responsible for the snarls on the Bypass every evening for the last few weeks. Commuters complained of remaining stuck on the Bypass for hours. Police blamed the snarls on the pothole-ridden stretches that slowed down traffic.

A stretch of around 9.5km of the 15.5km EM Bypass, between Science City and Briji Metro station, is riddled with potholes. The repairs between Monday night and Wednesday afternoon were done on this stretch. According to several commuters, the stretch between Science City and Ultadanga is in comparatively better condition.

Scores of potholes have formed on the Bypass since the start of the monsoon. The Kolkata Municipal Corporation (KMC) had been repairing potholes, but never with a targeted deadline like it did over the last two nights. Increased rainfall resulted in the formation of additional potholes.

From Monday night, the repairs began with a deadline to complete them by Tuesday night. But rain scuttled the plans. "We wanted to fill all potholes by Tuesday night, but overnight rain did not allow us to work for long. We continued the repairs on Wednesday afternoon," said a civic body official.

Senior engineers were present on the Bypass on Wednesday afternoon to oversee the repairs and ensure the work is completed by the evening. "There were three stretches that created most of the problems, and we have covered the potholes on all these stretches with bituminous mixture," said the official.

The three stretches were near Satyajit Ray Film and Television Institute, between Ruby and Tagore Park, and near Ambedkar Bridge.

"We noticed that it did not rain during the day for the last few days, but it rained at night. We decided to go ahead with the repairs in the afternoon on Wednesday," the official added.

He added that more repairs will be carried out in case additional potholes form because of rain.

Another civic body official said the heavy traffic on EM Bypass on any weekday and the snarls over the last week spurred the KMC to finish the repairs urgently.

Experts said the root problems, like damage in the underlying layers of a road or poor drainage, are some of the reasons why a road gets damaged frequently. "The root causes that lead to the formation of potholes must be addressed," said an expert.

The repairs did not address the undulations on the road or the root problems, like a drainage issue or the absence of an overhaul.

Sources in the state government said a fresh top bituminous layer was laid on the Bypass way back in 2009-10. In the 15 years since then, the road has been dug in multiple stretches for the construction of the New Garia-Airport Metro, but no new bituminous layer was put on the already battered surface.

"Only patch repairs were done as a quick-fix solution, but they were never meant to last for long," said an engineer of the state government.