SANRAL Initiates R4 Billion Upgrade of Africa’s Longest Road Tunnel to Expand N1 Traffic Capacity

South Africa's Huguenot Tunnel undergoes R4 billion expansion to four lanes. Explore how SANRAL's North Bore project will improve N1 safety and traffic flow.

By: AXL Media

Published: Apr 13, 2026, 5:27 AM EDT

Source: Information for this report was sourced from BusinessTech

Strategic Infrastructure Expansion Targets N1 Highway Bottlenecks

The South African National Roads Agency (SANRAL) has commenced a R4 billion overhaul of the Huguenot Tunnel, the longest road tunnel on the African continent. Spanning 3.9 kilometres, the tunnel is a critical link in the nation's transport infrastructure, having served over 100 million vehicles since its inauguration in 1988. The current project is designed to address the capacity limitations of the existing South Bore by finally commissioning the North Bore, which has remained closed to public traffic for nearly four decades.

North Bore Commissioning to Double Traffic Lane Capacity

The core objective of the upgrade is to transform the tunnel system from two lanes accommodating bi-directional traffic into a four lane system. Once the North Bore is fully equipped and operational, each tunnel will serve as a single directional carriageway with two lanes each. According to SANRAL, the project is currently in the procurement and commissioning phase, with the North Bore set to be completed first to allow for the temporary closure and total refurbishment of the aging South Bore.

Modernization of Aging Electrical and Mechanical Systems

After thirty eight years of continuous operation, the South Bore’s electrical and mechanical components have reached the end of their functional lifespan. SANRAL has emphasized that these systems require comprehensive replacement to align the facility with contemporary international safety standards. The upgrade will include the installation of an intelligent, distributed jet fan ventilation system to ensure optimal air supply, alongside a new high level reservoir dedicated to emergency fire response.