Route nationale 12
The Route nationale 12, or RN12, is a trunk road (nationale) in France connecting Paris with Brittany. The road forms part of European route E50. It is approximately 570 km (350 mi) long.
Until the 1950s, the RN 12 followed a different itinerary between Mayenne and Rennes. At Mayenne, the RN 12 was going south to Laval (now RN 162) then going west to Vitré and Rennes (now RD 57 and 857, former RN 157). The itinerary from nowadays was named RN 155 until Fougères and RN 177 from Fougères to Rennes.
The RN12 has been superseded into a freeway in a big part of its itinary; the old road has been re-numbered as the RD912, RD812 and RD712.
The road starts southwest of Paris as a branch of the Route nationale 10, the old road at Trappes starting as the Rue de Dreux and heading west. The new road is autoroute standard and starts as an extension of the RN286 at its junction with the A12 autoroute.
Both routes pass round the Étang de Saint-Quentin before merging at Plaisir; the old road course is often numbered RD912. The road heads west, crossing the Forêt des Quatre Piliers (184 m). The road now bypasses the small town of Houdan and crosses the river Eure into the city of Dreux, one of many that circle Paris.
The road leaves Dreux and heads broadly southwest through rolling countryside of southern Normandy. It passes the town of Saint-Lubin-des-Joncherets, now in the upper valley of the river Avre. It next comes to Verneuil-sur-Avre, where the RN26 heads northeast to Caen. The countryside is more wooded now as the road crosses the Les Bois Francs before coming to the Forêt du Perche.
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