Mumbai’s newest flyover is ‘melting’. But the outrage may not be justified

What are the videos actually showing?

The road surface on the flyover is made of mastic asphalt, which is a composition in which bitumen is poured and set. In high temperatures, bitumen softens and can appear to melt. “At present, Mumbai is witnessing high temperatures due to which the layer of bitumen on the road got melted. This is a very normal phenomenon,” said Pankaj Joshi, architect and urban planner.

The gravel visible on the surface is also not a sign of poor construction. These are stone aggregates — chips deliberately laid over the bitumen surface to create friction and prevent vehicles from skidding. Once traffic starts, the chips gradually settle into the surface under pressure. “The purpose of these stone chips is to ensure the road is not very smooth and there is friction that would prevent vehicles from skidding,” Joshi explained.

He added that it is possible the quantity of bitumen used was slightly more than required, which could explain the visible softening in the heat.

Cars drive past the visible damaged spots and uneven patches of the newly inaugurated Mrinaltai Gore Flyover Extension which was opened to the public on 06 June, at Oshiwara in Mumbai on 09 June 2026. (Express photo by Sankhadeep Banerjee)

Why does friction matter so much on this flyover?

The Mrinaltai Gore flyover has multiple curvatures, which makes surface friction especially critical. Structural engineer and architect Aditya Shenai said a textured, high-friction surface is not optional on a bridge like this. “Mumbai is a city that witnesses heavy rainfall, so it is important to have textured roads. Bridges that have curvatures need to have a high friction surface to prevent vehicles from skidding away from them,” he said.

A civic official pointed to what happens when this is neglected. After the Ghatkopar-Mankhurd flyover opened in 2020, multiple skidding incidents were reported because the surface was too smooth and no stone chips had been used. “We had to shut down the road for a few days to apply stone chips on them to ensure there was some friction on the surface,” the official said.

Cars past the visible damaged spots and uneven patches of the newly inaugurated Mrinaltai Gore Flyover Extension which was opened to the public on 06 June, at Oshiwara in Mumbai on 09 June 2026. (Express photo by Sankhadeep Banerjee)

So is the flyover defective?

Not necessarily and at least not based on what the videos show. The BMC has maintained that the current condition does not establish that the road was built defectively, and the experts broadly agree that what is visible is consistent with normal mastic asphalt behaviour in summer heat.

But the real verdict is still a week away. Monsoon is set to arrive over Mumbai shortly, and that is when the quality of the bitumen and the construction will be truly tested. “If the surface of the road is constructed by using poor bitumen or asphalt, then it will get washed away similar to how an orange skin comes out while peeling it,” Joshi warned. The flyover will either hold or it won’t. Mumbai will know soon enough.