The near-rainbow colours on some stretches of Kolkata’s streets – that have evoked wonder and bemusement in equal measure – will not remain for long and even a spell of rain could wash them off, Bengal urban development minister Agnimitra Paul told The Telegraph Online on Tuesday.
“The colours will last for barely four to five months. Emni chole jabe [It will go away on its own]. It might get washed away if it rains,” she said amid some airing safety concerns over the use of the colours.
The Gariahat Road flyover, the Chingrighata flyover, Red Road, Aurobindo Setu, Dhana Dhanye Setu, Chetla Bridge and two culverts on the Eastern Metropolitan Bypass are among the major thoroughfares that the Kolkata Municipal Corporation and Hooghly River Bridge Commissioners have selected ahead of Bengal’s biggest festival, Durga Puja, for the colour glow-up.
Paul had last week shared images of her drawing alpona at the Park Circus seven-point crossing, one of the busiest traffic intersections in the city.
The coloured roads have drawn criticism from some quarters for various reasons, including aesthetics and questions about finances.
“We wanted to beautify the city before our biggest festival,” Paul said. “Similar beautification is common in the United States, Iceland, Japan and some other countries. After seeing the images from these countries I decided to implement it here.
“This was entirely done through Corporate Social Responsibility (CSR) and no government fund was spent,” she added.
On Tuesday, Bengal Congress general secretary Ashutosh Chatterjee in a letter addressed to Paul and municipal commissioner and administrator of Kolkata Municipal Corporation Smita Pandey pointed to safety concerns arising from the use of oil-based and enamel glossy paints on the road surface.
The dangers, claimed the Congress leader, include low skid resistance, poor adhesion to bitumen and concrete, and lack of reflectivity.
“Glossy paint creates a smooth coating. When wet with water, oil or diesel, its coefficient of friction may fall from 0.6-0.7 to below 0.3. As a result, two-wheelers and cars may skid,” Chatterjee wrote in his letter.
“Road marking materials are used as alternatives to conventional oil paint because of their technical performance, durability and reflective properties.”
Chatterjee said the oil paints lack glass beads, which causes poor visibility at night and also when it rains.
“It releases fumes, takes a long time to dry, may soften under tyre heat and can become sticky,” Chatterjee argued.
He suggested brick red or terracotta for pedestrian plazas and raised speed-table surfaces, green for cycle tracks and electric vehicle charging bays, blue for parking bays for the specially abled and yellow hatching for junction boxes.
“Instead of ordinary paint, use anti-skid coloured surfacing containing bauxite chips. This provides a matte finish and better grip, even during the monsoon,” Chatterjee suggested.
“If you need to mark a private lane in the Kolkata area, use white and golden-yellow water-based matte road-marking paint from any recognised paint manufacturer along with drop-on glass beads. Keep at least 80 per cent of the tyre-running surface unpainted.”
The paints on select flyovers have been applied to only one flank.
“The above can only be done when our roads are healthy as you are already aware that numerous potholes and large damaged areas are on the current roads which is not only dangerous but invites accidents leading to loss of lives and also depreciation of tires,” wrote the Congress leader, urging repair of the damaged roads in the city — a concern shared by many residents.
As Durga Puja inaugurations have already started, the suggestions on the use of colour might be too late for now.
The minister does have the option of keeping these in mind when Park Street is painted around Christmas.
“Our festival season lasts from October to December. We plan to bring the colours to Park Street from Wood Street to the Chowringhee Road crossing before Christmas,” Paul said. “We are also planning to ply battery-operated carriages during Christmas on Park Street.”