A Calcutta High Court division bench of Chief Justice TS Sivagnanam and Justice Chaitali Chatterjee has sought a report from the state government in six weeks regarding the blue and white paint markings on the streets throughout the city and surrounding areas.

The advocate for the petitioner submitted, “Yellow-black and white-black colour (combinations) are used for road marking throughout the country. These colours are also used on national roads throughout the country. There is a scientific reason behind this. Yellow, black and white have clear visibility even in the darkness of night. So, blue and white should never be used for road marking. It has no scientific basis.”

Meanwhile, the state’s Advocate General Kishore Dutta submitted that he requires time to submit a report regarding the scientific reason behind the white and blue colour marking on the roads.”

A public interest litigation (PIL) was filed last week before the high court challenging the widespread use of blue and white colour schemes on road and bridge markings across Kolkata, contending that these colours pose a significant safety hazard to drivers. The PIL stated that the colour scheme deviates from the prescribed standards of the Indian Roads Congress (IRC) and that using yellow, black, and white—globally recognized traffic safety colours—would be more suitable.

The court acknowledged the concerns, noting the potential “dangers” of the current colour scheme, and adjourned the matter for further deliberation.

Blue and white road markings were painted on some Kolkata flyovers in 2012. In February 2023, the Kolkata Mayor asked metro authorities to paint corridors in blue and white. The Bengal PWD had also decided to install blue and white signboards on bridges, roads over bridges, and roads.