Apart from the Thalapady-Chengala and Vengalam-Ramanattukara corridors inaugurated in March, about 85 per cent of works have been completed in seven key stretches. The Kappirikadavu-Thalikulam, Thalikulam-Kodungallur and Kollam Bypass-Kadambattukonam spans are nearly 95 per cent complete, while the Taliparamba-Muzhuppilangad reach is 84 per cent and Azhiyur-Vengalam is 68 per cent. Contractors have had to source materials from neighbouring states owing to local shortages.
NHAI engineers attributed delays to the non-availability of rock aggregate and suitable earth within the state, and a recent ban on cross-border transportation of rock aggregate by Tamil Nadu further affected progress. The Public Works Department minister conducted three review meetings with NHAI officials to raise scarcity of materials, shortage of labour and monsoon-related slowdowns, and the chief minister has taken up the ban with neighbouring authorities in hopes of a resolution. Labour shortages were aggravated after many migrant workers from West Bengal left for state elections in March and have not returned, and local protests seeking underpasses have disrupted work at certain sites.
Inadequate drainage leading to severe water seepage caused structural failures and collapse of retaining walls at several locations, and investigations found shortcomings in subsoil and geotechnical surveys, earth-wall designs and monitoring. The ministry appointed an expert committee that recommended fresh geotechnical investigations, pullout tests on reinforced earth walls, reverification of ground conditions after improvement and stability analyses. Based on the panel's findings, NHAI has implemented rectification measures and imposed financial penalties worth multiple million (mn) Rs and temporary debarment on some major concessionaires.