The Tunnel Maurice-Lemaire, commonly known as the Tunnel de Sainte-Marie-aux-Mines is a former rail tunnel adapted to permit road traffic to drive between Sainte-Marie-aux-Mines (Haut-Rhin, Alsace) and Saint-Dié (Vosges, Lorraine) without needing to drive over the top of a mountain pass. The tunnel is long, which made it the longest road tunnel wholly within France. The tunnel owes its current name to Maurice Lemaire, a former Director General of the SNCF and a senior politician nationally and regionally during the third quarter of the twentieth century. Lemaire promoted the tunnel's modernisation.