A new numbering system on the territory of Paris Saclay
Why does the number of the lines change?
The bus network in Île-de-France is made up of nearly 1,900 lines, including 1,500 in the outer suburbs, and the numbering led to many lines bearing the same number.
The tools for searching for schedules and routes are regional, and it is therefore often complicated to find your line. For example, there were 13 bus lines with the number 10!
The numbers change so that each line in Île-de-France has a unique number.
How to find your way around the new issues?
Île-de-France has been divided into departments and sectors, each of which has a specific code. In the Paris Saclay area, bus lines now start with 46.
Whenever possible, the old number has been taken over to facilitate the change.
Example: line 1 becomes line 4601.
The numbers of the Express lines begin with the number of their department.
Example: The Express line 91-05 becomes the 9105.
What will this new number bring to users?
Users will be able to find their bus line more easily, as it will be the only one in Île-de-France to have this number!
Thus, when we type her number into the search engines of the application or iledefrance-mobilites.fr site, we will be able to directly access the information about her.
When do the lines change number?
With the exception of lines 4602, 4621 and 4622, which were renumbered on 22 April 2025, all lines in the Paris Saclay territory will change their number as ofMonday 15 September 2025.
You can also follow our news on X: @Saclay_IDFM
From the start of the school year, find us on your lines to answer all your questions!
The dates will be communicated at the end of the summer on the page X of your territory.
See you again!