South Africa has driven into a R200 billion-plus pothole

 ·9 Mar 2022

Transport minister Fikile Mbalula says South Africa is facing a significant roads maintenance backlog which has continued to grow over the last decade.

Asked about how many potholes the country has in a recent written parliamentary Q&A, Mbalula said it was difficult to quantify this figure as it was impossible to totally eradicate potholes in the country.

He added that the emergence of potholes depends entirely on the extent and nature of rainfall in that month or year.

“It is true that potholes cannot be eradicated; however, to ensure that roads are properly maintained, my department is providing support – supplementary funding of just over R12 billion per annum to provinces – through the Provincial Road Maintenance Grant that is ringfenced for the maintenance, rehabilitation, strengthening of paved roads, re-gravelling, gravel road blading and blacktop patching including pothole repairs.”

“The value of maintenance backlogs to address the road condition was estimated to be R197 billion in 2013. Based on the assessment of the 2017 data and additional data being collected, this figure is expected to increase and the process to update this calculation is work in progress.”

Further data provided by Mbalula shows a significant number of the country’s paved roads are in a poor or very poor condition. The minister has previously indicated that 80% of South Africa’s roads have reached the end of their design life.

Mbalula said there are numerous factors influencing the performance of a pavement and the development of potholes, with the following five considered the most influential:

  • Traffic is the most important factor influencing pavement performance. The performance of pavements is mostly influenced by the loading magnitude, configuration and the number of load repetitions by heavy vehicles.
  • Moisture can significantly weaken the support strength of natural gravel materials, especially the subgrade. Moisture can enter the pavement structure through cracks and holes in the surface, laterally through the subgrade, and from the underlying water table through capillary action. The result of moisture ingress is the lubrication of soil particles, loss of particle interlock and subsequent particle displacement resulting in pavement failure.
  •  The subgrade is the underlying soil that supports the applied wheel loads. If the subgrade is too weak to support the wheel loads, the pavement will flex excessively which ultimately causes the pavement to fail. If natural variations in the composition of the subgrade are not adequately addressed by the pavement design, significant differences in pavement performance will be experienced.
  •  Failure to obtain proper compaction, improper moisture conditions during construction, quality of materials, and accurate layer thickness (after compaction) all directly affect the performance of a pavement. These conditions stress the need for skilled staff and the importance of good inspection and quality control procedures during construction.
  • Pavement performance depends on what, when, and how maintenance is performed. No matter how well the pavement is built, it will deteriorate over time based upon the above-mentioned factors.

Read: 80% of South Africa’s roads have reached the end of their design life: minister

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