CHENNAI: The first concrete road in India was built in Chennai by the British in 1914. But even decades later, there are only a few stretches in the city that are laid with concrete. After a Madras High Court directive in 2017, the Chennai Corporation claims that it has laid about 20,000 concrete roads in core city areas. But except for a few junctions and main roads, concrete roads are still a rare sighting in the city, when compared to tar roads.
Experts and residents said that this is a project the Corporation must concentrate on, as concrete roads laid more than five years ago are in good shape when even newly laid tar roads are lying in shambles.
Good roads
A few concrete road stretches that have been in good condition for many years are Harrington Road in Chetpet, Loop Road in Santhome, Kodambakkam High Road junction, Chennai Bypass Road near Porur toll plaza, and Kazhikundram Road in Taramani. In contrast, newly laid roads in Kundrathur, Vanagaram, Porur and even along Anna Salai are already coming off.
The biggest problem with tar roads laid in recent times is that due to poor quality the binder or top layer gets damaged very easily, especially on roads where heavy vehicles ply, say experts. Because of this, the other three layers beneath get exposed. This causes dust to kick up and loose gravel stones to scatter on the road making it dangerous for motorists.
“Studies show that there are less chances of potholes forming on concrete roads. While tar roads need to be relaid every three to four years, concrete roads last for more than 20 years. Though the initial cost is more, concrete roads require almost no maintenance for more than 10-20 years,” said Sivasubramaniam J, an expert on transport planning and systems in ITDP.
Bengaluru has taken up the project of white topping on a massive scale which involves laying of concrete on existing tar roads. While this project is facing a few hurdles and has missed its deadline for completion, it maybe a project worth pursuing for Chennai, said experts. “As concrete roads need time to cure, it cannot be used immediately after it’s laid. But tar roads can be used the next day itself. This is the biggest drawback for concrete roads. But its high durability makes it a better alternative,” said Sivasubramaniam.
Learning lessons
On the other hand, senior officials from the Chennai Corporation said that as the remaining 14,000 roads fall in extended areas like Ambattur, Manali, Madhavaram and Puzhuthivakkam, where civic works are still ongoing, it is taking more time to concretise them.
“Unlike Bengaluru, Chennai is an unplanned city. Also, Chennai is a much bigger city with varying soil types. In slushy soil, only tar roads can be laid. Also minerals like gypsum and magnesium will deplete in the soil as cement doesn’t allow water to percolate. So tar roads cannot be completely ignored,” said an official.
In such areas where civic works are still in progress, pavement blocks can be used to cover the road instead of cement as they can be taken off easily if the road has to be dug up again. This is the technique being used in Bengaluru and Hyderabad. But milling of existing tar roads is crucial before adding the white topping said Basavaraj Kabade, a senior official from Bengaluru Corporation.
“Traffic congestion and dust pollution has largely come down along the outer ring road in Bengaluru after white topping was done. But a utility map has to be prepared before starting this work. We coordinated with the water and electricity agency and identified spots which needs to be dug up again,” he said.