The 3.9-kilometre Huguenot Tunnel, the longest road tunnel in Africa, is undergoing a major R4 billion upgrade led by the South African National Roads Agency (SANRAL), aimed at transforming the structure into a modern dual-tunnel system.

Opened in March 1988, the South Bore currently carries bi-directional traffic, while the North Bore remains closed to vehicles and is now in the commissioning phase ahead of full operational readiness. SANRAL plans to expand the system from two to four lanes, with each bore ultimately handling one-way traffic.

The upgrade programme includes refurbishment of the ageing South Bore and completion of the North Bore, with tenders confirmed in 2024. Although construction was initially expected to begin in 2025, the project remains in the procurement phase.

SANRAL says the tunnel’s electrical and mechanical systems have reached the end of their operational life and require full replacement to meet international safety standards.

Once complete, the upgraded system will operate with two lanes in each direction, improving traffic flow along the N1 corridor between Cape Town and the interior. The tunnel currently accommodates about 13,000 vehicles daily, saving motorists significant travel time compared to the Du Toitskloof Pass.

Planned enhancements include advanced ventilation systems, air quality and traffic sensors, wind mitigation barriers on the Hugo’s River Viaduct, and energy-saving wind turbines at tunnel entrances. A high-level water reservoir is also part of emergency fire safety planning.

The project is expected to take three to five years to complete, with sequencing beginning with the North Bore before refurbishment of the South Bore.

Beyond transport efficiency, the site has attracted scientific interest. Researchers have proposed the development of the Paarl Africa Underground Laboratory, which could become the first underground physics laboratory of its kind on the continent.