Creative solutions help SA pave new ways

R oad construction projects in South Africa continue to offer opportunities for innovation and the creative application of engineering solutions.

SANRAL is leading the way on the African continent with its design and engineering of roads, bridges and vital transport infrastructure.

On the N2 Wild Coast Road, construction has started on the new bridge across the Mtentu River Gorge. When completed, the bridge will be one of the longest main-span, balanced-cantilever bridges in the world. A similar mega-bridge will be built across the Msikaba gorge along the route.

Another innovative project is the construction of an integral-design bridge at Van Zyl Spruit in the Free State. The design eliminates the installation of metal expansion joints and bearings and has the potential to extend the life of the bridge.

Working with researchers from the University of Pretoria, the engineering team has installed a battery of instruments on the bridge, including strain gauges to measure stress, temperature sensors and earth pressure sensors. The study will have an influence on the wider use of integral design in South Africa in the future.

A single tag lifts all booms

Road users can now use a single toll account and one tag fitted to their vehicles to pass through toll plazas across the country.

This innovation, known as interoperability, offers cashless travel for road users and adds significantly to the travel experience, comfort and safety on the primary national road network.

A national transaction clearing house for toll payments was developed as part of the Gauteng

electronic toll collection system. This provides the platform for interoperability for all toll transactions taking place at toll plazas on the network.

Since its introduction in 2017, electronic toll transactions have grown to almost 20% of activities at toll plazas. It offers road users a convenient alternative and helps to reduce congestion at toll plazas during peak travel times.

The project has received the Fulton Award for Innovation from the Concrete Society of South Africa. SANRAL has now developed in-house capacity for Innovation in the application of smart technology to road management and the pioneering of geotechnical solutions within the engineering and construction sectors.

Top brains test ideas at SANRAL Hub

The Technical Innovation Hub in Cape Town is producing smart solutions to address challenges in the fields of road safety, asset preservation and environmental and energy conservation.

Engineering graduates who qualified with SANRAL bursaries are putting their academic and technical training to work by coming up with smart innovations that can solve problems in the transportation sector.

Among the projects under way are:

A pilot study to use drones to inspect the state of rockfall catch fences at Sir Lowry’s Pass in the Cape peninsula. Drones are already used to inspect bridges and slopes, but the new application will reduce safety risks on a very busy stretch of road that is vital to the Western Cape’s economy.
A robotic flagger for roadworks on high-volume routes is being developed. This will reduce the safety risks to road flaggers working on hazardous spots on the routes.
A panoramic camera system will eliminate “blind spots” on the freeway incident detection systems. The device uses image-stitching software to create a single panoramic image. Initial testing in the Western Cape has already produced promising results.

Innovation will reduce cost of road construction

Nanotechnology might soon be used to stabilise inherently unstable road building materials at road construction sites.

Technical experts from SANRAL have developed a theoretical solution for the application of

nanotechnology-based resins normally used in industrial processes.

The aim is to ensure a wide range of lower grade and marginal stone materials could be stabilised and successfully used in construction. This will

make road building more affordable and reduce its environmental impact, because materials can be sourced closer to the construction sites.

The solution will be tested when a suitably situated construction project comes on stream.