Prior to its construction, N1 road users wishing to travel north from Cape Town had the choice of two mountain passes, the Bains Kloof Pass and the Du Toits Kloof Pass, which were hazardous.
P A de Villiers, chief engineer identified the Du Toits Kloof Pass as the preferred route to the interior and had championed the construction of a road tunnel as early as 1937.
The main Huguenot tunnel excavation started in 1984 and proceeded on two headings using the drill and blast method.
Half a million cubic metres of rock was excavated and used for fill on the western approach road and as concrete aggregate for the tunnel lining.
South African VKE and Swiss Electrowatt, Zurich consulting engineers carried out the design of the Huguenot Tunnel, which was known as the largest and most costly single project that the South African Roads board had ever undertaken.
An economic impact study carried out in 1983 predicted that the income to persons in the Western Cape attributed to the construction of the tunnel would stand at R200-million by 1988.
The cost of the tunnel when it opened was R202,6-million and subsequent improvements to the roads infrastructure at the eastern side of the toll road have seen the figure increase to R500-million.
Around 200 Labourers, 50 artisans and 15 managerial staff were directly employed at the height of the construction period between 1984 and 1987, and some 35 consultants in various professions contributed to the project between 1975 and 1988.
Seven main contractors, 121 subcontractors and 810 suppliers reportedly spent 10 million man-hours bringing this project to fruition.
The tunnel is 3913 m long and shortens the journey between Cape Town and Worcester by 11 km and eliminates a rise and fall of 400 m over the old pass.
The tunnel also handles 8 500 vehicles a day on average with peaks occurring during school holidays and at Easter.
The operators of the tunnel have apparently achieved a Nosa5 Star rating for staff safety. Tunnel fires are a constant source of concern particularly in view of the horrendous European tunnel fires that have claimed so many lives in recent years, however, the Huguenot Tunnel differs from these tunnels in that while all operate as bi-directional tunnels, they are single bore tunnels with no parallel escape route.
The Huguenot Tunnel has the unfinished North Bore connected to it by 11 cross connections, which act as places of refuge in emergencies and also allow safe evacuation to the outside and access by the fire brigades to fight the fire from relative safety.