Keralam PWD wary of wider adoption of white-topped roads despite proven durability

File image of a white-topped road

Although white-topped roads are considered better suited to Keralam’s climatic conditions and urban stretches, the Public Works Department (PWD) remains reluctant to adopt the technology on a wider scale, citing relatively high initial construction costs. This is despite the successful execution of a model white-topped road by the department in Alappuzha, which demonstrated the feasibility of the technology in the State.

White-topping involves laying an additional layer of cement concrete over an existing bituminous (asphalt) road. The technology offers several advantages over conventional asphalt roads, particularly in urban areas of Keralam that experience heavy rainfall, high summer temperatures and severe traffic congestion.

Speaking to The Hindu, former PWD Minister G. Sudhakaran, said the department experimented with white-topping (concrete overlay) on a pilot basis along a 7.2-km stretch at a cost of ₹24.5 crore in 2018 as part of the City Road Improvement Project in Alappuzha. The road continues to stand the test of time, demonstrating greater durability without requiring any maintenance so far, he said.

Under normal conditions, white-topped roads have a lifespan of more than 20 years, whereas conventional asphalt roads in stretches carrying heavy traffic require maintenance and resurfacing every two years. Concrete surfaces are also less susceptible to pothole formation caused by water infiltration and repeated vehicular movement, he said.

Mr. Sudhakaran said contractors were also not happy with the idea of adopting white-topping. The State government launched the pilot project in 2018 after sending a team to Bengaluru, where around 900 km of city roads had been white-topped. The Alappuzha project was subsequently taken up based on the technical studies conducted by the PWD team, he added.

He also raised the issue with PWD Minister P.K. Basheer in the Assembly through a question last week, seeking the latter’s views on extending the technology to other roads based on the experience of the Alappuzha project. However, Mr. Basheer said that although white-topping offered greater durability than conventional bituminous surfaces, it involved a very high initial capital investment. Consequently, the department had not explored the possibility of adopting the technology on PWD roads in other parts of the State.

Sources in the Kerala Highway Research Institute (KHRI) acknowledged that the State faced certain limitations in adopting the technology, particularly in terms of initial investment, construction time and the maintenance of underground utilities. White-topped roads are around three to four times more expensive to construct than conventional asphalt roads. However, when the long-term maintenance costs of asphalt roads are taken into account, the overall expenditure on the two types of roads may not differ significantly, despite the higher initial investment required for white-topping, they said.

They also pointed out that asphalt roads offered slightly better riding comfort than rigid concrete surfaces. While routine maintenance requirements were lower for white-topped roads, repairing damaged concrete sections could be more complicated, as it might involve replacing individual concrete panels.

Nevertheless, considering the other advantages, including greater resistance to water-related deterioration in Keralam, which receives around 3,000 mm of rain in a year, better visibility at night, reduced dependence on artificial road lighting, lower surface temperatures, and a reduced urban heat island effect, white-topping could be a viable option for critical urban stretches in Keralam, said KHRI sources. The PWD has recently set an ambitious target to upgrade 15,000 km of roads in the State to Bituminous Macadam and Bituminous Concrete (BMBC) standards over the next five years.