The opening of Line 18 of the Grand Paris Express, the inauguration of the Tzen 4 bus in Essonne, the deployment of MF19 trains on Lines 3b and 7b of the Paris metro, and the arrival of 60 RER NG trains on Line E... All these developments point to a busy year ahead. In 2026, many changes are expected in the public transportation landscape across Paris and Île-de-France.
New services are also on the horizon for car users, especially in the Val-d'Oise and the Essonne. Île-de-France Mobilités (IDFM) has announced the launch of four new express bus lines starting in 2026, with the first being Line 9517. Scheduled for rollout in March 2026, this new bus line aims to replace the popular Roissybus service, which will cease operations on March 1. Line 9517 will run between Argenteuil and Roissypôle, passing through Saint-Denis Pleyel. The goal? To give tourists and travelers quicker access to Paris Charles de Gaulle Airport, by avoiding traffic jams around Paris and at the airport gates, and offering connections to Line 14 at Saint-Denis Pleyel, explains IDFM in a press release.
Before the launch of Line 9517, two other express bus routes will make their debut in Val-d'Oise, including Line 9513, expected to start in January 2026. This route will connect Cergy-Préfecture to Argenteuil via Sannois and Franconville in just 45 minutes, offering "a bus every 15 minutes during rush hours and a service six days a week from 5:30 a.m. to 10:30 p.m. (until 8:35 p.m. on Saturdays)," the authorities have announced.
The 9514 line connecting Cergy-Préfecture to Chars via Osny, Cormeilles-en-Vexin, Frémécourt, and Marines is also expected to launch in January 2026. According to Île-de-France Mobilités, buses will operate from 6 a.m. to 8 p.m., with a bus every 30 minutes.
Lastly, the Essonne department will not be overlooked, as the Evry-Fontainebleau express line is set to welcome its first travelers in March 2026. This project aims to streamline commutes between the Fontainebleau area, the Bière region, Ponthierry, and the employment and university hub in Evry.
Official website
www.iledefrance-mobilites.fr
