TECHNICAL DESIGN CONSIDERATIONS

As a road authority, SANRAL’s primary sphere of influence is engineering. However, the N2 and N3 upgrade programme will allow for the facilitation of an integrated approach to improve safety for all road users.

It is not just human factors, such as speeding, not wearing seatbelts or careless driving, that increase the risk of a crash occurring. Poor road design can also cause crashes.

Designing for all users - During the upgrade programme, the N2 and N3 will be designed with the needs of all road users in mind – including pedestrians, non-motorised road users and local communities and businesses. The safety of motorists and pedestrians alike, will be a central consideration in every decision made about construction.

Quieter pavements - By using noise reducing asphalt mixes and specialized concrete grinding techniques, motorists will be able to travel along the N2 and N3 peacefully with less tyre noise.

Robust pavements - More damage is caused to roads by heavy vehicles than light vehicles. To cater for growing volumes of freight traffic on the N2 and N3, the pavement design methods and materials to be used in sections most prone to deterioration will be carefully considered.

Environmental considerations - During construction on the N2 and N3, SANRAL

commits to enhancing eco-efficiency and identifying and managing or eliminating environmental risks. SANRAL will encourage planting partnerships in its quest to re-populate the entire road reserve to a similar state it was in before construction. Already during the upgrading of the Hammarsdale Interchange, several plant species, including a range of specially protected bulbs and aloes growing along the busy N3, have been translocated to a temporary nursery to save them from being destroyed.

Aesthetically pleasing - Bridge structures are built to last for decades and often serve as a gateway to a community. Good bridge design not only considers structural integrity, but also aesthetics. Therefore, SANRAL believes it is important for the new bridge structures along the N2 and N3 to be pleasing to the eye. The redesigned EB Cloete Interchange (Spaghetti Junction) - 3D image shown here - will feature a cable suspended bridge from an iconic arch.

Geometric design - The upgrades on the N2 and N3 will utilise geometric design to optimise efficiency and safety while minimising cost and environmental damage. The smooth flow of traffic will be balanced.

Safety improvements - Apart from resolving chronic traffic congestion by creating greater mobility through construction of additional traffic lanes, the upgrading of the N2 and N3 will result in increased safety. Dangerous curves will be ironed out. Unsafe intersections will be redesigned. Major realignment of the N3 highway will take place at Key Ridge (3D image shown here) where the steep grades cause major traffic congestion and serious crashes.