A year after an expert committee flagged 351 reinforced soil (RS) retaining walls along the National Highway 66 stretch from Kasaragod to Thiruvananthapuram as potentially unsafe due to their inadequate load-bearing capacity, no corrective measures have been taken. The report has neither been made public nor acted upon, with the National Highways Authority of India (NHAI) limiting its response largely to soil testing.

The Centre had constituted a four-member expert committee on May 24, 2025, following the collapse of a retaining wall along the highway at Kooriyad in Malappuram. The panel was headed by Dr Kishore Kumar, former chief scientist at the Central Road Research Institute (CRRI), New Delhi, and was tasked with examining the RS walls and slope protection works along NH 66.

The committee inspected various locations between June 11 and July 14 and submitted its report on August 4, 2025.

It recommended soil testing and an assessment of the underlying geological structure and ground strength to determine the extent of the deficiencies. The Centre subsequently appointed 10 geotechnical agencies to conduct soil tests, but no significant follow-up measures were taken.

Although the Centre had assured that the design and construction of each retaining wall would be reviewed and necessary action initiated, this too did not materialise.

The NHAI initiated another round of expert inspections after a retaining wall collapsed at Mylakkad in Kollam on December 5, 2025. More agencies were also appointed to conduct detailed soil investigations.

However, further work was confined to locations where retaining walls had already collapsed.

At Kooriyad, a 377-metre viaduct was constructed at the contractor's expense to replace the collapsed retaining wall. Steps were also taken to construct a 120-metre viaduct in place of the damaged wall along the Kollam-Kadambattukonam stretch.

Meanwhile, a technical and safety assessment was conducted after girders under construction collapsed at the Aroor-Thuravoor elevated highway project.

Locals raise concerns
Civil engineer and Kooriyad native P K Riyas said local residents had raised concerns about flaws in the NH 66 design, particularly regarding construction in areas such as Kooriyad, but their warnings were ignored.

"We had pointed out that the construction in areas such as Kooriyad could be technically unsound when we first saw the NH 66 design. The highway collapsed even before the work was completed," he said.

He added that concerns about the structural strength and inadequate width of the nearby Panampuzhakkadavu bridge had also gone unaddressed. "The service road runs over a drainage channel. Residents and elected representatives pointed out several shortcomings based on their limited technical knowledge. However, what we witnessed was construction being rushed without proper scientific assessments," Riyas said.