driving
French roads suffer from cracks following summer droughts
Repairs underway as clay soil shrinkage and expansion impact roads
Efforts to repair roads damaged by record droughts and heatwaves this summer are underway in several French departments.
Roads built on clay soils, which can shrink and expand in periods of dry and wet weather and eventually begin to crack, are most at risk.
Deep cracks forming on road surfaces can damage vehicles, and in some cases even cause accidents. Vehicles of all types are impacted, including trucks, cars, and motorbikes.
Roads in Vienne are among those being repaired. Other departments have recorded extensive damages, including in Haute-Garonne where around 300km of roads are affected.
Further repairs are expected, although local authorities will need to raise funds – in Vienne, a supplementary budget increase of €140,000 for repairs has been approved.
In addition, repairs may need to wait for weather conditions to settle, as significant changes could see any improvements quickly reversed.
What causes the problem?
Many are likely to be aware of retrait-gonflement des argiles (RGA), a phenomenon that sees clay soils shrink and expand due to drastic changes in weather.
Soils can shrink during periods of drought as moisture is sucked out of them, before being rehydrated and expanding rapidly when rainfall returns.
Persistent changes and a cycle of swelling and shrinking can damage structures above ground, leading to cracks in homes.
Millions of properties across France are at risk, but the issue extends to other structures built on these soils, including roads.
Soil shrinkage issues are exacerbated by periods of extreme weather, particularly prolonged droughts and warm weather – as seen this summer – and intense rain, which has followed the summer droughts in some areas of France.
Prolonged droughts followed by heavy rainfall can see soils contract then expand several times, quickening damage.
On top of weather patterns, roads are also impacted by the roots of nearby trees and bushes which can suck moisture out of soils underneath roads, leading to further cracks.
The video below by French journalist Jamy Gourmaud, explains how roads are impacted by clay shrinkage.
What can drivers do?
Drivers are unfortunately limited in their ability to take action on the matter.
The government has an official map showing where clay soil shrinkage issues are most prominent, but this is largely directed at property owners and not for drivers.
If you notice cracks in a road you often use, it is worth reporting it to the local mairie (for communal roads), the department (departmental roads) or the relevant concessionaire (for motorways).
Motoring association 40 MIllions d’automobilistes also has an online service to report damaged roads (potholes and other issues as well as cracks). More information can be seen in our article here, as well as links to the service.
