NEW DELHI: The road transport and highways ministry has admitted design failures, weak quality assurance and over-reliance on highway builders as some of the factors for certain newly built highway stretches with concrete pavement collapsing in rain-prone and low-lying areas, according to the latest report of Public Accounts Committee (PAC) of Parliament.Raising concerns over the “indiscriminate shift” from bituminous to concrete roads without adequate assessment, the committee said this has led to poor-quality outcomes, delays, and potential wastage of public funds. The panel has recommended the ministry and National Highways Authority of India (NHAI) adopt a mandatory, evidence-based framework for selecting pavement materials — bituminous, concrete, or otherwise — based on site-specific technical and environmental assessments. This, it said, should be integrated into the preparation of Detailed Project Reports (DPRs).The panel referred to specific instances, including a section on Delhi–Vadodara Expressway that got damaged. “These roads, which were expected to offer long-term service with minimal maintenance are found to have developed premature cracks, surface distress, and failures in pavement quality concrete (PQC), often within a short period of completion,” the report mentioned.The committee also took note of how the entire task of project preparation, execution and even supervision are left to contractors and consultants while NHAI’s internal role is limited to formal approvals. It observed that such “delegation of responsibility weakens accountability”, especially when supervision consultants also fail to flag design deficiencies. It referred to the Kooriyad collapse in Kerala which was attributed to inaccurate geotechnical assessments and poor oversight by both highway builder and the supervision consultant.“The committee are of the view that the methodology being followed by NHAI could help it escape responsibility but this brings bad repute to NHAI as an organisation.While design scrutiny is important, implementation of approved design should also be ensured and no short cut measures to reduce costs by the concessionaire/ sub contractors may be permitted,” the panel said.The PAC has also called out the ministry on the practice of subcontracting in NH projects — primary contractor assigns or outsources its work to other parties. Taking note of ministry’s submission that much of road infrastructure is executed by sub-contractors, who might not be accountable under the primary contract framework, the committee said “unchecked layering of contractors and sub-contractors” has led to “diffusion of accountability”, where NHAI has limited leverage to enforce quality standards or timely deliveryIt has recommended the ministry to discourage subcontracting beyond one level — contractor to one subcontractor. “If further subcontracting is absolutely necessary, it should only be allowed with special approval from NHAI. NHAI must ensure that all subcontractors are registered, get prior approval, and are clearly documented,” it said.