Open in 1963,the coastal road RN1 links the towns of La Possession and Saint-Denis. It is situated  at the base of an instable cliff (from 100m to 300m high) and directly lie the Indian Ocean. It is then regularly exposed to wave overtopping, landslides and falling blocks that hamper the traffic. During cyclone crisis, the decision of closing and re-opening this road is a real issue because of its economic and strategic importance but also for emergency services transport. The anticipation of the traffic conditions is also highly important to limit the risk of car crash.

Some historical examples (source DDRM La Réunion):

February 2007 – Gamède – Erosion of the sea front.

January 2013 – Felleng – Wave overtopping on the road, road temporarily closed.