Rehabilitation of the N17 East Toll Road
The N17’s begun as a regional route in the 1960s before becoming a dual carriageway in the 1080s that served as an international link between Johannesburg and Swaziland (Oshoek). With time it has been upgraded to meet the ever increasing traffic demands.
Fast forward to the present and there were a number of shortcomings on the route between Leandra and Oshoek, which needed to be addressed including, deteriorated pavement conditions; numerous 4-way stop signs; low travelling speed design; poor vertical and horizontal geometric standards; high crash rates; as well as the route traversing through numerous towns increasing safety risks and delaying travellers.
The recent upgrades sought to address these issues and more. South African National Roads Agency (SANRAL) commenced in 2001 with feasibility studies and shortly thereafter appointed consultants for the rehabilitation, upgrading and design of new sections of the N17 from Springs to Ermelo (approximately 290 km).
South Africa’s road network has become a transportation superhighway ferrying cargo, taxis, private vehicles and goods throughout the country. Through the years, the roads have undergone upgrades to ensure safety and efficiency.
The R1.3 billion (US$ 135.5 million )project has been divided into sections for ease of construction management. There are six sections comprising of both newly constructed roads combined with road upgrades. In addition to road construction, a number of additional structures such as bridges and toll plazas are being erected.
There will be about 25 km of new road construction including sections between Leandra and Trichardt (21km), past Trichardt (3km) and in Bethal (1.5km). The remaining route will be upgraded to improved geometric standards such as improvements to the vertical and horizontal alignment, paved shoulders, interchanges at grade intersections and climbing/passing lanes. Additionally, the methodology being implemented now uses modern pavement management techniques ensuring at least a 20-year design life.
Road Section Upgrades
The section of the N17 from Johannesburg to Springs is mostly a dual carriageway and is already a national toll route. Hence the road works started from Springs and effectively ended in Ermelo.
- Section Between Springs and Leandra—rehabilitation (48km)
- Rehabilitation of the pavement
- Construction of interchanges at Nigel and Devon to address high accident rate
- Adding passing and climbing lanes
- Resurfacing with skid resistant asphalt
- Completion March 2010
- Section Between Leandra to Leven—new construction (21.5km)
- Construction of new road to eliminate current detour through the town of Leandra.
- Initially it will be one carriageway of a future dual carriageway
- Paved shoulders and passing / climbing lanes
- A main toll plaza will be constructed on this section
- Completion May 2010
- Section Between Leven and Trichardt—N Build and Rehabilitate (12km)
- Construction of new provincial road parallel to the N17 from end of previous contract to Secunda road interchange
- Rehabilitation of the pavement
- Construction of interchange at Secunda road
- Adding passing / climbing lanes
- Construction of new road to eliminate current detour through town of Trichardt
- New bridges and access roads
- Completed by September 2011
- Section Between Trichardt and Bethal—Rehabilitation (24km)
- Pavement rehabilitation
- Improvement of intersections
- Addition of passing / climbing lanes
- New alignment through town of Bethal to eliminate the current staggered route
- Construction of interchanges at high volume intersections
- Construction of a mainline toll plaza
- Completion March 2011
- Section Between Bethal and Davel—Rehabilitation (20km)
- Pavement rehabilitation
- Improvement to horizontal and vertical alignment
- Improvement of intersections
- Adding passing / climbing lanes
- Completion March 2011
- Section between Davel and Ermelo—Rehabilitation (35km)
- Pavement rehabilitation
- Improvement to horizontal and vertical alignment
- Improvement of intersections
- Adding passing / climbing lanes
- Completion Sept 2011
Overcoming the Odds
As reported by Alan Agaienz of SANRAL the road developments are progressing quite well and all sections seem to be on track for their scheduled completion dates. Yet, there have been some obstacles.
“One of the difficulties encountered with upgrading and rehabilitating a road is that we get settlements and deflections of the old pavement. Although, it can be brought up to a good level, it is not as perfect as starting from scratch. So, the places where we tie an existing road with widening and bypass lanes it is not easy to get the levels to tie up perfectly evenly.”
Other challenges reported by Agaienz related to working while the road was in full operation and the precise juggling that was necessary in order to ensure a steady flow of traffic while utilising methods of alternating usable lanes and ‘stop-goes’.
Yet, possibly the most daunting aspect of this project has been the section between Leven and Trichardt. The team had to divide this section into three parts upon the discovery of an incredible amount of underground services.
“These services had to be deviated to Wildebeesfontein where the capable reservoirs are. Present ground pipes had to be dropped and doubled to allow our lowering of the ground to create a bridge. This was costly,” says Agaienz.
Sustainable Development
Upon completion it is envisaged that the rehabilitation upgrading and expansion of this section of the N17 will ensure that an attractive economic link will be preserved and maintained from Gauteng to Swaziland, enhancing export opportunities and economic growth in both South Africa and Swaziland.
In addition to ensuring a smooth flow for the country’s economy, the road upgrades will provide employment opportunities for local residents and provide increased safety for pedestrians, motorist and their vehicles.
PROJECT TEAM
| Client | South African National Roads Agency Ltd (SANRAL) |
Engineers |
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Contractor |
