After crossing the RN 13, the RN 15 follows the Seine towards Vernon. The RN 15 straightens and leaves the river, passing the town of Gaillon. The road runs parallel to the A13 autoroute and passes through the Forêt de Louviers heading North and over the river at Pont-de-l'Arche onto the right bank of the Seine.
The road follows the river bank overlooked by surrounding cliffs including the Roches de Saint-Adrien. The road meets the Route nationale 14 and enters the capital of Normandy, Rouen.
The N15 heads Northwest from the city centre and towards Yvetot. It enters the town of Yvetot to continue westwards. The road passes near the town of Bolbec, passes the A29 autoroute, Harfleur and enters Le Havre, ending at the city town hall.
History
The N 15 was numbered N 13BIS from the 1950s until the end of the 1970s reclassification scheme. The RN 13BIS replaced the RN 182 (between Bonnières-sur-Seine and Rouen) and the RN 14 (between Rouen and Le Havre). Until 1972, the RN 15 was going from Pontoise to Dieppe; this road has been changed in RD 915 except in the Eure where it is called RD 15BIS. In 2006, the RN 15 has also been changed in a départementale and is now numbered RD 6015 in the Eure and Seine-Maritimedépartements and D 915 in the Yvelines. Nowadays, the RN 15 is limited to the crossing of Rouen.