Aubisque descent heavily damaged following thunderstorms.
Stage 19 could be modified if the authorities think they won't be able to repair the road in time.
There has been several precedents these past few years:
- In 2017, there has been a similar event on the col d'Agnes (stage 13) with a damaged road. They managed to repair it in less than a month, allowing the race to take the usual route.
- In 2016, there were concerns regarding possible landslides on the col de la Ramaz (stage 20). For safety, col de la Ramaz has been removed from the Etape du Tour amateur event, but the route was unchanged for the Tour - however the Caravane had to avoid it.
- In 2015, a huge landslide above the Tunnel du Chambon (stage 20) damaged the structure of the tunnel and made it unsuitable for the race. After several inspections, it was too dangerous for the safety of the riders, and even later, they realized they had to dig an entire new tunnel to replace the old one, which would take 18 months - and had also to create an additional road on the other side of the lac du Chambon. As a result for theT Tour, the col du Galibier had to be replaced by the col de la Croix-de-Fer.
- In 2013, thunderstorms destroyed roads on the col du Tourmalet (not planned for this year) and in the Garonne valley between Saint-Béat and Bagnères-de-Luchon, threatening to remove the col de Menté from the route. But the damage was lower than expected, and after repairs and cleaning, the route was kept as is.
- In 2008, a huge risk of crumblings on the col de Larche forced ASO to take another route three months before the race: they had to move the start city from Digne-les-Bains to Embrun, and take the col Agnel for the first time in its history.