NHAI Mandates Independent Design Verification for Critical Highway Bridges
The National Highways Authority of India (NHAI) has issued a circular mandating a uniform system of independent design verification for critical bridges and complex structures on national highway projects, effective December 1, 2026. This policy applies to projects executed under Engineering, Procurement and Construction (EPC), Hybrid Annuity Model (HAM), and Build-Operate-Transfer (BOT) modes.
Scope of Verification Requirements
The new verification protocol targets high-risk infrastructure, specifically major river bridges with a design discharge of at least 3,000 cubic metres per second, structures with an individual effective span of 40 metres or more, and other special structures identified by the authority. Under the procedure, contractors must submit their designs to the Authority's Engineer or Independent Engineer for initial review. Following this, they are required to propose three institutions or firms from an NHAI-approved panel, from which the regional office will select an agency to conduct the independent review, according to Swarajya.
Approximately 12 Indian Institutes of Technology, including IIT Delhi, IIT Bombay, IIT Roorkee, and IIT Kharagpur, have collaborated with the authority to serve on the approved technical design verification panel, according to ET Infra.
Implementation and Compliance
The independent review process will encompass a comprehensive examination of design calculations, structural analysis, drawings, and relevant hydrological and hydraulic studies. Contractors are responsible for incorporating any observations or necessary changes identified during this review, subject to the approval of the Authority's Engineer or Independent Engineer.
The cost of this proof-checking process will be borne by the contractor. For existing contracts where this requirement is introduced as an additional obligation, the NHAI will process it as a variation or change of scope. The mandate covers all new projects as well as those awarded before December 1, 2026, provided that design vetting or proof-checking has not yet commenced. Projects where the vetting process is already complete are generally exempt, though additional checks may be mutually agreed upon for particularly complex structures.
Why independent bridge review matters
Design verification is different from routine visual inspection of an existing bridge. Before construction, an independent checker can review structural loads, geotechnical assumptions, seismic or flood conditions, material specifications and unusual construction stages. Once a bridge is open, separate inspection and maintenance systems are still needed to detect corrosion, scour or damage caused by changing traffic. For highway users, the strength of the policy lies in whether reviewers are genuinely independent, deficiencies are documented and corrective work is completed before a design proceeds. Implementing a rule on paper without adequate engineering capacity or public accountability will not by itself establish that every critical bridge is safe.