Kolkata rainbow flyover paint: the anti-skid standard missing from the row

By Prakhar Shahi

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Agnimitra Paul, West Bengal's urban development minister, who led the rainbow paint drive on Kolkata flyovers

Bikes skidded on the painted Chingrighata flyover on 14 October and studs went in a day later. A road-marking code summary sets a 45 BPN skid floor; nobody has said whether the paint met it.

Original report

What anti-skid standard should the paint on Kolkata's rainbow flyovers meet? A summary of the Indian Roads Congress road-marking code says a marking surface should reach at least 45 BPN of skid resistance, the same as the road around it (InfraLens, 2015), and that benchmark had not featured in the reports we compared after motorcycles skidded on the rainbow-painted Chingrighata flyover on 14 October 2026.

By 15 October the state had closed that flyover overnight, fitted grip blocks and studs, and scraped a second bridge, Hindustan Times reported (Hindustan Times, 2026). The probe ordered by chief minister Suvendu Adhikari has not yet reported, and nobody on record has said what the paint was made of.

Here is the event in one paragraph. A dashcam video that spread on X on Wednesday showed motorcycles sliding on the painted Chingrighata flyover after a drizzle. The Times of India counted three bikes, while Hindustan Times and India Today reported riders falling (Times of India, 2026; Hindustan Times, 2026; India Today, 2026).

The road-marking code sets a 45 BPN floor

IRC:35, the code of practice for road markings, wants markings at least 45 BPN of skid resistance, according to the InfraLens summary of the code (InfraLens, 2015). BPN is the reading on a British Pendulum skid test. The summary names anti-skid aggregate or textured tape as ways to reach it, and gives a recommended minimum friction coefficient of 0.45.

Those figures come from a secondary summary. We did not read the IRC text itself.

Set that against the warning in the row. Congress general secretary Ashutosh Chatterjee wrote to the minister and to KMC commissioner Smita Pandey that wet glossy paint can drop the friction coefficient from 0.6-0.7 to below 0.3, The Indian Express reported (Indian Express, 2026). That is his claim, not a measurement. If it held, 0.3 would be 0.15 short of the 0.45 minimum, a third below it.

Whether the Kolkata paint cleared that floor depends on what the paint was, and the answers conflict.

The minister says anti-skid; an engineer says ordinary paint

Urban development minister Agnimitra Paul, who led the painting drive, said anti-skid paint was used (India Today, 2026). She told India Today: "It is not permanent paint. It will wash away when it rains."

A senior state traffic-planning engineer told the Times of India the coating looks more like oil-based or emulsion paint than thermoplastic (Times of India, 2026). The chief minister was more guarded. "Bikes can skid for various reasons," Adhikari said, the same report noted (Times of India, 2026).

No paint brand or specification has been published in the reports we read. None says whether the Gariahat flyover or Red Road were tested for friction.

What is on record is how fast the state moved once the video spread.

From viral video to studs in a day

Paul has named three painted stretches, all done in rainbow hues before Durga Puja: the Gariahat flyover in the south, the Chingrighata flyover in the east and a section of Red Road in central Kolkata (Hindustan Times, 2026). This is the sequence we built from the reports:

Several other claims in the row have not been proved either way.

What is verified and what is not

That leaves one more open question: the bill.

Who paid for the paint, and who pays to remove it

Paul said the painting was funded through corporate social responsibility (CSR) money. "No government money was used for this," she told The Indian Express (Indian Express, 2026). The Trinamool Congress has asked who will pay to remove it (India Today, 2026; Indian Express, 2026).

What happens next

The probe ordered by the chief minister has no published finding or report date in the sources we read. For riders, the questions it needs to answer are the paint's specification and whether each painted stretch meets the 45 BPN marking floor in the code summary.

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References

How we did this

We compared four reports published on 14 and 15 October 2026, from Hindustan Times, India Today, The Indian Express and the Times of India. Most led on the probe, the political row or the paint type; none gave the road-marking code's skid-resistance figure. We added that benchmark from the InfraLens summary of IRC:35, built one timeline of the fixes across Chingrighata, Gariahat and Asansol, and sorted each claim into verified and unverified. We did not read the IRC code itself, and we did not test the paint.

This story was produced, reviewed, edited and verified by the reporter before publication, with AI assistance where required.

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