Kolkata’s rainbow-painted Chingrighata flyover has been identified as a potential skid-risk zone for two-wheelers after an IIT-Kharagpur road-safety expert found that ageing mastic asphalt, multiple paint layers, curves and inadequate surface friction were combining to make the road dangerous, particularly during drizzle.
The inspection by road-safety and transportation expert Bhargab Maitra followed viral videos of motorcycles skidding on the freshly painted surface. Police have since deployed civic volunteers to discourage riders from stopping to film reels and are shifting from restricting two-wheelers mainly during rain to enforcing lower speeds throughout the day.
Maitra said the mastic asphalt layer was more than 13 years old and had lost its effectiveness in providing the required frictional resistance. He also found that repeated painting had reduced the roughness of the surface. “With every layer, brightness has improved but friction has been compromised,” he observed.
The risk is higher for motorcycles because they have lower stability and a smaller tyre contact area than larger vehicles. The flyover’s downward gradients and curves further increase the possibility of riders losing control, especially when the surface is wet. Police said two-wheelers would continue to be stopped completely during rain.
The Kolkata Police has put up warning signage and is regulating motorcycles on the flyover. Officers said the maximum permissible speed would be reduced, traffic entering the structure would be staggered and stricter speed restrictions would be considered throughout the day. A 40-kmph limit and the installation of speed cameras were among Maitra’s recommendations.
Police have also asked civic volunteers to prevent riders from stopping, slowing abruptly or filming while crossing the colourful stretch. The intervention became necessary after the flyover drew bikers following the circulation of skidding videos online. Officers said none of the riders involved in Wednesday’s incidents had reported to the police, limiting the scope for an accident-specific investigation.
The Kolkata Metropolitan Development Authority has begun manual and mechanised removal of paint in an effort to restore surface roughness. Maitra also recommended replacing the ageing mastic layer and conducting safety audits of all city flyovers every six months.
Environmental activist SM Ghosh and other concerned citizens have sought written clarification from paint manufacturers on whether the coating used on the flyover was road-grade thermoplastic material and whether the prescribed application standards were followed. Police and KMDA’s immediate measures remain focused on reducing speed, managing two-wheeler movement and removing the paint while corrective work continues.
