The road crosses the A86 autoroute and meets the banks of the River Seine.
Following this, the road runs through various towns in Val d'Oise, such as Pierrelaye, then crosses the River Oise where it enters the city of Pontoise.
The D14 continues West where it merges with the A15 autoroute at Osny and becomes the N14 again, leaving Paris and entering le Vexin Français.
The road continues West and re-enters the Seine valley as it approaches the capital of Normandy, Rouen.
The section Rouen - Yvetot - Le Havre of the Route nationale 15 is the former itinerary of the RN 14.