Kolkata’s Colourful ‘Rainbow Roads’ Raise Safety Concerns as Bikes Skid on Wet Surfaces

Kolkata’s colourful road markings, designed to brighten public spaces and improve the city’s visual appeal, have prompted concerns about two-wheeler safety after reports of motorcycles skidding on painted sections of the road. The issue highlights a challenge for urban planners: street beautification must not compromise the grip riders need, particularly during and after rainfall.

Painted road surfaces can become hazardous when their texture and friction differ from those of ordinary asphalt. For motorcyclists, who rely on the contact between two tyres and the road to maintain balance, even a small reduction in traction can increase the risk of losing control while braking, turning or travelling over a slippery patch.

Why Painted Roads Can Become Slippery

The main concern is the material used to colour the road. Conventional road surfaces generally have a rough texture that helps tyres maintain contact with the pavement. Some decorative coatings, however, can create a smoother finish, depending on their composition, application method and condition.

Rain can make the problem more pronounced. Water forms a thin layer between the tyre and the road, potentially reducing friction. If the painted surface is already relatively smooth, a rider may have less grip available when negotiating a turn or slowing down.

The risk can also depend on the type of paint or coating, the aggregates mixed into it, the quality of installation and how much the surface has worn over time. Not every coloured road is inherently dangerous, and the presence of paint alone does not establish that a stretch is unsafe. The key factor is whether the finished surface provides adequate skid resistance under real-world conditions.

Two-wheelers can be particularly vulnerable because riders must maintain balance while responding to changes in traction. Sudden braking, sharp steering movements or acceleration over a slippery section can make a skid more likely, especially in wet weather.

How Cities Can Make Roads More Attractive Without Compromising Safety

Urban designers do not necessarily have to abandon colourful streets to address these concerns. A safer approach is to select materials specifically engineered for roads rather than relying on decorative coatings intended primarily for appearance.

One option is to use anti-skid road coatings containing suitable aggregates that create a textured surface. These materials can improve tyre grip while allowing roads, pedestrian crossings and public spaces to retain distinctive colours. However, their performance depends on correct installation, maintenance and testing under wet conditions.

Authorities should also assess a proposed design before applying it across busy streets. Trial sections can be tested for friction, drainage and durability, including how the surface behaves after repeated exposure to rain and traffic. Independent safety assessments can help determine whether the chosen materials meet the required standards.

Another consideration is where colourful treatments are installed. Decorative designs may be more appropriate for pedestrian plazas, traffic-calmed neighbourhoods and spaces with limited vehicle movement than for sections where motorcycles regularly make sharp turns or brake suddenly. Any road treatment must remain compatible with traffic flow, visibility and the needs of different road users.

Maintenance is equally important. Dust, oil, worn coatings and standing water can affect road grip. Regular inspections should identify deteriorating surfaces, drainage problems and locations where riders repeatedly experience difficulty. Where a coating proves unsafe, repairs or replacement should take priority over preserving its appearance.

What Motorcyclists Can Do on Wet, Painted Roads

Until road conditions are improved, riders can reduce some risks by approaching painted sections cautiously, especially during rainfall. Maintaining a moderate speed, leaving sufficient distance from other vehicles and avoiding sudden braking or sharp steering movements can help preserve control.

Motorcyclists should also keep their tyres in good condition and check that tread depth is adequate. On slippery surfaces, abrupt changes in speed or direction can be particularly difficult to manage. Riders should remain alert to road markings, metal covers, oil patches and pooled water, all of which may affect traction.

These precautions cannot compensate for an inadequately designed road surface, but they can help riders respond more safely to changing conditions.

Kolkata’s experience illustrates a wider lesson for cities investing in attractive public infrastructure. Street design should be judged not only by how it looks in photographs but also by how it performs during everyday travel and adverse weather.

Colourful roads can contribute to a more welcoming urban environment, provided safety remains central to the design process. Using tested materials, conducting wet-weather assessments and maintaining road surfaces can help cities balance visual appeal with reliable traction for two-wheelers and other traffic