The N4 is the main link between South Africa and Mozambique, and is one of the busiest roads in South Africa, averaging 140,000 VPD. WBHO delivered 8.5km of the N4 Nelspruit Northern Ring Road, involving:
- Construction of nine bridges, totalling over 700 metres, some comprising post tensioned cast insitu decks and some with a precast beam and slab superstructure. Bridges crossed rivers, roads and railway lines. Bridges were constructed over two navigable rivers, the Crocodile River and the Nelspruit River. These rivers become floodways during the rainy season. Consequently, construction of the footings for the bridges required the use of coffer dams, created using sandbags, then backfilled with rock
- 600,000m3 of cut, including 200,000m3 of blasting in hard rock to a depth of six metres
- The project was delivered in an area of environmentally-sensitive wetlands within the savannah biome of South Africa.