[1] The road commences at Brest docks passing the visitor attractions Oceanopolis and Botanical Gardens.
Thereafter the road turns south crossing the River Elom on a modern bridge the Pont de l'Iroise.
The road passes the town of Plougastel Daoulas and alongside the coast (a series of submerged valleys) in the Parc Naturale D'Armorique.
The road passes the Airport of Lann-Bihoué and forms the northern by-pass for Lorient over the Rivers Scorff and Blavet past Hennebont and a junction with the N24 to Rennes.
The road continues south east to the town of Vannes on the northern shore of the Gulf of Morbihan.