A51 autoroute

It is the long-term project to connect Marseille to Grenoble via Aix-en-Provence, the Durance Valley and the Hautes-Alpes department.

The motorway passes the cities of Aix-en-Provence, Pertuis, Manosque, Sisteron and then Digne-les-Bains and Tallard.

Its main section connects Marseille to Aix-en-Provence and the Durance Valley to the north of Sisteron (Saulce).

This includes 4.5 km which is a single carriageway through the Tunnel of Sinard and over the Viaduct de Monestier.

However the 2011 edition of the National Scheme of Transport Infrastructure (SNIT) did not include the completion of this section.