NHAI Floats ₹959 Crore Tender for Viaducts, Tunnel and Underpasses on NH 66.

The National Highways Authority of India (NHAI) has floated a fresh engineering, procurement and construction (EPC) tender worth around ₹959.25 crore for major safety upgrades on the Kazhakkoottam–Kadampattukonam stretch of NH 66. The proposed works include 12 viaducts, a cut-and-cover tunnel and additional pedestrian underpasses aimed at improving road safety and traffic movement.

The tender, issued on Monday, has been invited for a period of 45 days, with bids scheduled to be opened after the submission deadline on August 21. The project has a completion timeline of 18 months, followed by a 10-year maintenance period.

The new viaducts are planned at key locations including Technopark Phase-IV, CRPF Pallipuram and Mamom near the Attingal bypass. The additional structures were introduced after a detailed safety review of the NH 66 widening project, particularly following a series of accidents reported in Kollam and Malappuram.

However, sources indicated that the additional works could have an impact on the already delayed highway project, which is currently under execution. The Kazhakkoottam–Kadampattukonam section is part of Kerala’s six-laning programme for NH 66 and is being executed separately from the newly proposed safety structures.

The existing highway works are being carried out by Pune-based RKC Infrastructure Ltd, which took over the project following earlier contractual changes. The ongoing civil works will continue under the existing agreement, while the newly sanctioned viaducts, tunnel and underpasses will be executed under the fresh EPC contract after the tender is awarded. The deadline for the ongoing package has been extended until March 31, 2027.

A senior NHAI official said the new safety works would not delay the ongoing construction. “This is fresh work and it is required, especially in Kerala where the terrain is vulnerable due to heavy rainfall. Traffic movement will not be disrupted once the ongoing work is completed,” the official said.

The proposed viaducts are expected to improve traffic flow through densely populated and low-lying stretches by reducing conflict points on the highway. The cut-and-cover tunnel and pedestrian underpasses are designed to provide safer crossings for local residents and minimise risky highway-level crossings.

The contractor handling the Kazhakkoottam–Kadampattukonam package said the project has achieved around 75% physical progress. Nearly 80% of the service roads along the corridor have also been completed, improving local connectivity while main carriageway works continue.

The Kazhakkoottam–Kadampattukonam corridor is a crucial section of Kerala’s NH 66 widening project, linking Thiruvananthapuram with northern districts and serving heavy passenger and freight traffic, including vehicles connected to the Vizhinjam International Seaport.

The latest tender represents a major modification to the original project design, with NHAI incorporating additional safety infrastructure into the highway upgrade. Similar interventions are likely to be considered on other NH 66 stretches after detailed safety assessments.

The project has faced several challenges that affected construction speed. Rising costs and shortages of key materials such as bitumen, PVC and aggregates, partly due to global supply disruptions, created difficulties for contractors and affected execution schedules.

Monsoon-related issues, administrative delays and logistical challenges also slowed progress. Delays in digital surveys, land acquisition procedures and the transfer of revenue officials during election periods affected certain sections. Restrictions and delays in quarry operations further impacted the availability of construction materials required for embankment works.

Labour shortages added to the difficulties, with several migrant workers returning to their home states during election periods, temporarily reducing workforce availability at construction sites.