After the successful implementation of lines 4602, 4621 and 4622 as part of the first phase of the restructuring of the bus network in April 2025, the overhaul of the lines in the Paris Saclay area continues.
As of 15 September, new changes are being implemented. They concern more particularly the municipalities of Marcoussis, Orsay, Palaiseau and Les Ulis and are concomitant with the renumbering of the network's lines.
In a few words:
- lines 5 and DM10A merge and become the new line 4605 whose offer is reinforced and expanded (creation of a Sunday offer),
- Line 4627 is created to better serve the Paris-Saclay Hospital from Les Ulis and Orsay,
- Lines 4665 and 4666 take over the school services of the former DM10A to serve the Essouriau and Blaise Pascal high schools.
Line 4605
This line connects the commune of Marcoussis to that of Orsay via Les Ulis, from Monday to Sunday.
In Marcoussis, it runs between the Chêne Rond and Poteau Blanc stops, with a partial terminus at Étang Neuf during peak hours on weekdays.
In Les Ulis, it serves the Ulis 2 Shopping Centre on the Aubrac side and offers many connections with the other bus lines (line 4621 for Massy-Palaiseau - Cévennes or Stade stops, line 9 for the Plateau de Saclay - Bourgogne stop).
In Orsay, it terminates at the RER B Orsay-Ville station and offers direct access to Paris.
Line 4605 is + simple, + passages, + amplitude!
» Operation : Monday to Sunday
» Amplitude : 5:00 am - 10:05 pm on weekdays, 5:28 am - 10:05 pm on Saturday and 7:20 am - 9:35 pm on Sunday
» Weekly frequency : 12 to 24 minutes during rush hour and 30 minutes on the slack
Saturday frequency : 30 minutes in the morning, 20 minutes in the afternoon
» Sunday frequency : 60 minutes in the morning, 30 minutes in the afternoon
Map of line 4605
Line 4627
This new line provides a link between the municipalities of Les Ulis and Orsay to the new Paris-Saclay Hospital. It allows you to access the hospital site without any connections and quickly.
It also offers access to the town halls of Les Ulis and Orsay as well as to the Corbeville and École Polytechnique sectors.
Line 4627 is + direct and + amplitude!
» Operation : Monday to Saturday
» Amplitude : 6:05 am - 10:15 pm on weekdays, 6:15 am - 10:15 pm on Saturdays
» Weekly frequency : 30 minutes
» Saturday frequency : 30 minutes
Map of line 4627
The 4665 line
This regular school line serves the Lycée de l'Essouriau (in Les Ulis) from Marcoussis.
» Operation : Monday to Saturday
» Amplitude : 7:41 am - 6:15 pm on weekdays, 7:49 am - 12:50 pm on Saturdays
» Weekly frequency : 3 return trips / 4 returns per day
» Frequency on Saturday : 2 round trips / 2 return trips per Saturday
Map of line 4665
The 4666 line
This regular school line serves the Blaise Pascal high school (Orsay) from Marcoussis via Villejust.
» Operation : Monday to Friday
» Amplitude : 6:57 a.m. and 5:36 p.m.
» Weekly frequency : 1 return trip / 1 return trip per day
Map of line 4666
From the start of the school year, find us in the field to answer all your questions!
Find our presence on our X account: @Saclay_IDFM