Repairs on the Science City-bound flank of Bridge No. 4 started from Monday night and will take more than a month, an official of the Kolkata Metropolitan Development Authority (KMDA), the custodian of the bridge, said.

The flank will remain closed between 11pm and 6am, said the official.

Paver blocks are being installed over the approach from the Park Circus end of the bridge.

“We have noted that this stretch breaks every monsoon. We undertake repairs, yet the surface wears off and large potholes spring up on it. We decided to install paver blocks to avoid repeated damage on the surface,” said the official.

KMDA officials sought 50 days to complete the work, but the police have given two weeks for now. “We are expecting that more time will be given to us after the first two weeks,” said the official.

The progress is slow because of the rain. The project will cost over ₹50 lakh.

Stretches of several roads in the city that used to get damaged repeatedly during the monsoon have been built with paver blocks. Roads in the Calcutta Port area and stretches of Biswa Bangla Sarani near Nicco Park in Salt Lake are among them.