South Africa’s road network is mostly gravel, meaning that it is mostly unsurfaced/unpaved roads made up of gravel and fine gradients, like silt or clay. It is also, undeniably, in poor condition.

The country’s road network is 750,000km long, but only about 21.08% of the road network is paved, while the majority of about 78.92% is gravel. The South African National Roads Agency Limited (SANRAL) manages the country’s national road network, which is about 13.54% of the paved road network, while management of the rest of the paved road network is split between provinces, metros, and municipalities.

As presented in Figure 1 below, provincial gravel roads make up about 30% of the road network, municipal gravel roads make up about 29%, and metros make up about 2%. About 18% of the road network is unproclaimed (all gravel). (Department of Transport,
2025)

Figure 1 : South Africa’s gravel road network and management of the gravel network

Source: (Department of Transport, 2025)

The SAICE 2022 Infrastructure Report Card for South Africa rates provincial and municipal unpaved roads at the lowest rating of E: Unfit for purpose. Such gravel roads make up the vast majority of the country’s road network but are largely in an unsatisfactory condition from insufficient capacity and funding. (SAICE, 2022)

Why so much gravel?

Due to funding constraints, investment decisions around transport infrastructure aim to prioritise projects that will provide the greatest (net) economic benefits. Economic evaluations and life-cycle cost analysis assist such investment decisions, estimating the costs and benefits of a proposed transport project (e.g., roads), allowing the comparison of project options.

Upgrading gravel roads to paved roads has significant upfront capital costs, meaning that it is more viable to maintain a gravel road in areas with low volumes of traffic. As of 2024, typical unit costs of upgrading to a Low Volume Surfaced Road are reported as R1.56 million per kilometre on average, but can cost up to R5.3 million depending on the seal standard used. By contrast, re-gravelling commercial roads costs between R0.9 million to R1.3 million per kilometre. (Committee of Transport Officials , 2024)

However, even with the higher upfront capital costs, upgrading roads is preferred as it ultimately results in cost savings that accrue over the road’s lifetime through reduced frequency of road maintenance and rehabilitation (i.e., a sealed paved road will remain in suitable condition much longer than a gravel road, which may require re-gravelling several times a year) (Committee of Transport Officials , 2024) .

Unfortunately, since such cost-savings from road upgrading accrue over time, traditional road infrastructure planning in South Africa has often used a "defer and maintain" approach, postponing expensive road upgrades while investing in maintenance to extend the life of existing road surfaces. As a result, the majority of the country’s road network is unpaved gravel roads.

Gravel in the rain

In contrast with sealed paved roads, gravel roads are fundamentally vulnerable to moisture. When heavy rain falls, these roads lose shape and material as moisture infiltration leads to erosion, potholes, slipperiness, etc. In severe conditions, gravel roads become impassable after rainfall.

In South Africa, one doesn’t even need to find the research 3 that links rainfall intensity to unpaved road erosion – simply go for a drive on a gravel road after rain and admire the sheer magnitude of the potholes you see. While obvious, this has economic implications; gravel roads in high-rainfall areas require more frequent maintenance and rehabilitation (e.g., re-gravelling), meaning higher costs across a gravel road’s life.

The effects of climate change: rain on the horizon

South Africa’s transport infrastructure is exposed to extreme weather, particularly rainfall and flooding, and such events are expected to increase in intensity due to climate change.

Historically, South Africa’s rainfall increases from West to East, with the highest rainfall occurring across Limpopo, Mpumalanga, KwaZulu-Natal, and the Northern parts of the Eastern Cape. (Water Research Commission, 2025)

Climate change is expected to influence the country’s weather patterns, with higher rainfall predicted in certain areas (McBride & Dyson, 2023; Siyakatshana, Ndayi, & Mokoena, 2024) . The government’s National Climate Change Information System – Provincial Climate Narratives discusses how eastern and coastal provinces can be expected to face increased rainfall under climate change 4 . Similarly, the CSIR Green Book projects that extreme rainfall events may increase in frequency over most of the central interior and east coast. Therefore, while the country may face overall-drier conditions, some provinces, as shown in Figure 2 below, are expected to face extreme rainfall and flooding. (DFFE, 2018; CSIR, 2025)

Figure 2 : Provinces most at risk of increased rainfall and flooding from climate change

Source: Author’s own, based on predicted rainfall frequency from climate change

The effect of climate change and resulting extreme rainfall is not just a prediction but a reality South Africa currently faces: Over the past two decades, there has been an increase in recorded weather-related disaster events in South Africa, with the two highest events recorded being flooding and storms (Siyakatshana, Ndayi, & Mokoena, 2024) . The 2022 Durban floods, which claimed 544 lives, displacing tens of thousands, have been found to have been significantly worsened by the increased rainfall effect of climate change (Wits University, 2025) .

Roads at risk

We know South Africa is full of gravel roads, and we know certain provinces are expected to face higher rainfall and possible floods. So, which gravel roads are in these high-risk provinces?

National Treasury’s Provincial Budgets and Expenditure Review: 2020/21 – 2026/27 provides estimates for each province’s gravel road network length as of 2024, displayed in Table 1 . However, considering the DoT estimates of the total provincial road network at 273,621 km (about 35,277 km greater than the below estimate of 238,334 km), these numbers may be conservative estimates of the provincial gravel road network.

Source: (National Treasury, 2025)

Across the high-risk provinces, namely Limpopo, Mpumalanga, and KwaZulu-Natal, 46,814 km of unpaved roads exist which are at risk of increased rainfall and flooding from climate change. Adding the unpaved road network from the moderate-risk Free State, Eastern Cape, and Western Cape brings the total up to 147,507km of roads.

Using the lower-bound estimate of 46,814 km equates to 6.24% of the entire current national road network. However, these provincial estimates do not include municipal and metro gravel roads (233,684km) or unproclaimed roads (131,919km). If similar geographic distributions were applied, a significant additional portion of this 365,603km would also face extreme weather risks.

Road infrastructure inclusion in climate resilience strategies

The exacerbated deterioration of the country’s gravel roads from climate change would bring several significant socioeconomic costs:

 – Road users would face higher vehicle operating costs (from increased vehicle damage and maintenance) and longer travel times          (having to travel slower for roads in worse condition). Road agencies would ultimately face higher costs for road maintenance and        rehabilitation.

 – The wider economic benefits of road infrastructure would be lost, such as through the disruption of logistic supply chains.

 – The socioeconomic benefits of the road network would be lost. Across Sub-Saharan Africa, rural communities rely on the low-                volume roads that make up the bulk of road networks (CSIR Consortium, 2020) . This is the case in South Africa, where its rural              road network of unpaved gravel roads connects rural communities to essential services, markets, and economic opportunities.

Therefore, the extensive portion of the country’s gravel road network at risk to climate change has dire consequences and cannot be ignored. Climate change compels a fundamental shift in how South Africa approaches road infrastructure in vulnerable regions. Pre-emptive upgrades of gravel roads and regular maintenance of paved roads are among the most effective strategies for enhancing climate resilience. As climate change increases the frequency and severity of road damage, failure to upgrade will impose rising fiscal costs and socioeconomic burdens. (Lacambra, et al., 2020)

South Africa must integrate road infrastructure resilience into its climate adaptation strategies, prioritising gravel road upgrades and other such infrastructure investments.

References

Committee of Transport Officials . (2024). TRH 24 UPGRADING OF UNPAVED ROADS Draft Standard (DS). The South African National Roads Agency SOC Limited .

CSIR. (2025). Climate Change. Retrieved from Green Book: https://pta-gis-2- web1.csir.co.za/portal/apps/GBCascade/index.html?appid=b161b2f892194ed5938374fe2192e537

CSIR Consortium. (2020). Designing Climate-Resilient Roads for Long-Term Rural Access. ReCAP.

DBSA; The World Bank. (2023). GOING BEYOND THE INFRASTRUCTURE FUNDING GAP: A SOUTH AFRICAN PERSPECTIVE. The World Bank. Department of Transport. (2025). Roads. Retrieved from Transport: https://www.transport.gov.za/?page_id=1042

DFFE. (2018). Provincial Climate Narratives. Retrieved from National Climate Change Information System: https://nccis.environment.gov.za/climate- information/provincial-climate-narratives

Lacambra, C., Molloy, D., Lacambra, J., Leroux, I., Klossner, L., Talari, M., . . . Johnson-Bell, L. (2020). Factsheet Resilience Solutions for the Road Sector in South Africa. IDB.

McBride, C., & Dyson, L. (2023). Increasing Rainfall Extremes in SA. Retrieved from University of Pretoria: https://www.up.ac.za/research-matters/news/post_3149538-increasing-rainfall-extremes-in-sa-

National Government. (2025). Eastern Cape June floods declared a national disaster. Retrieved from SAnews: https://www.sanews.gov.za/south-africa/eastern-cape-june-floods-declared-national-disaster

National Treasury. (2025). PROVINCIAL BUDGETS AND EXPENDITURE REVIEW:2020/21 – 2026/27. National Treasury.

Ngezahayo, E., Ghataora, G. S., & Burrow, M. P. (2019). Factors Affecting Erosion in Unpaved Roads. 4th World Congress on Civil, Structural, and Environmental Engineering.

Ramaphosa, C. (2024). Remarks by President Cyril Ramaphosa at the Transport Summit on Universal Accessibility, Birchwood Conference Centre, Ekurhuleni. The Presidency of South Africa.

SAICE. (2022). SAICE 2022 Infrastructure Report Card for South Africa. South African Institution of Civil Engineering .

Siyakatshana, D. N., Ndayi, V., & Mokoena, R. (2024). Climate impacts on South African transport infrastructure. CSIR.

Valencia-Gallego, V., & Montoya, L. J. (2024). Erosion Mechanisms in Unpaved Roads: Effects of Slope, Rainfall, and Soil type. Air, Soil and Water Research. Water Research Commission. (2025). Rainfall in South Africa. Retrieved from South Africa: https://southafrica.co.za/rainfall-south-africa.html

Wits University. (2025). Climate change significantly worsened deadly 2022 Durban floods. Retrieved from UNIVERSITY OF WITWATERSTRAND: https://www.wits.ac.za/news/latest-news/research-news/2025/2025-07/climate-change-significantly-worsened-deadly-2022-durban-floods.html