From 1 January 2023, the company Francilité Saint-Quentin-en-Yvelines, a subsidiary of the Lacroix & Savac Group, operates the lines of the "Saint-Quentin-en-Yvelines" territory on behalf of Île-de-France Mobilités.
This territory, made up of 12 municipalities, serves 24 municipalities and 7 stations with 51 lines:
6 strong lines structuring the territory, the most frequented
Strong lines: 8, 414, 415, 417, 418 and 465
- 8 : Les Clayes-sous-Bois Bus station <=> Plaisir-Grignon Gare </=>
- 414: <=> Trappes-Gare Montigny – Saint-Exupéry</=>
- 415: Le Mesnil – Place du Mesnil <=> Bois d'Arcy – Méliès – Croix Bonnet</=>
- 417 : Trappes – <=> Gare La Verrière – Gare</=>
- 418: Trappes – <=> Gare Plaisir – Z.I. The Gâtines</=>
- 465 : Montigny -Saint-Quentin Gare <=> Guyancourt – Villaroy</=>
17 main lines complementing the strong lines
Main lines: 9, 10, 44, 45, 401, 419, 420, 422, 423, 424, 439, 461, 463, 464, 467 and 468
- 9 : Plaisir Marché <=> Plaisir-Grigon Station Platform 9</=>
- 10 : Plaisir-Grignon Station Platform 2 <=> Bus Station P. Delouvrier</=>
- 44 : Plaisir – Grignon <=> Versailles Chantiers</=>
- 45 : Villepreux <=> Chavenay</=>
- 401 : Versailles – <=> Maurepas Village</=> station construction site
- 419 : Montigny-le-Bretonneux – Franco-Japanese Institute <=> Magny-les-Hameaux – Mérantais</=>
- 420 : La Verrière <=> Trappes Pissaloup</=> station
- 422: La Verrière <=> Elancourt Les Côtes</=> station
- 423 : La Verrière Gare <=> La Verrière Gare</=>
- 424 : La Verrière Gare <=> La Verrière Gare</=>
- 439: Versailles Chantiers <=> Gare Voisins – Chamfleury</=>
- 461 : Montigny – Saint-Quentin <=> Magny-Mérantais</=> station
- 463 : Montigny – Saint-Quentin Gare <=> Elancourt – De Lattre de Tassigny</=>
- 464 : Montigny – Saint-Quentin Gare <=> Saint-Rémy-lès-Chevreuse – Gare</=>
- 467 : Montigny – Saint Quentin <=> Guyancourt Station – Villaroy</=>
- 468 : Montigny – Saint-Quentin <=> Guyancourt Station – E. Viollet-le-Duc</=>
4 local lines finely meshing the territory
Local lines: 402, 430, 431 and 459
- 402 : Trappes-Gare <=> La Verrière - Station</=>
- 430 : Trappes Gare <=> Trappes Gare (urban circuit)</=>
- 431 : Trappes <=> Hennequin Trappes Hennequin</=>
- 459 : The glass roof of <=> Elancourt station France Miniature</=>
7 one-off lines dedicated to employment areas and transporting residents to large work areas
Point lines: 6, 20, 50, 440, 441, 444, 460, 466
- 6 : Plaisir-Grignon station platform 4 <=> trappes Pissaloup</=>
- 20 : Les Clayes-Sous-Bois Bus station <=> Noisy-Le-Roi Gare</=>
- 50 : Plaisir-Grignon Station Platform 3 <=> Montigny-le-Bretonneux Bus station des Prés</=>
- 440: Montigny – Lycée Descartes <=> Versailles Chantiers Gare</=>
- 441 : Maurepas Grand'Mare <=> Guyancourt Trou Berger / Guyancourt 60 Arpents - Technocentre</=>
- 444 : Montigny St-Quentin Gare <=> Magny-les-Hameaux Le Buisson</=>
- 460: Guyancourt Odyssey <=> technocentre Montigny Saint-Quentin-Gare</=>
- 466 : Montigny St-Quentin <=> Guyancourt Station – 60 arpents - Technocentre</=>
17 school lines dedicated to transporting students to schools in the region
School lines: 42, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, AQ, BL, CSP, JV and TG
- 42 : Les Clayes-sous-Bois <=> Villepreux</=>
- 448 : Le Mesnil-St-Denis Place du Mesnil <=> Montigny Les Bretonneux Collège St-François d'Assise</=>
- 449 : Elancourt France Miniature ó<=> BUC-Lycée Franco-Allemand</=>
- 450 : Montigny-le-Bretonneux Collège St-François d'Assise <=> Maurepas Grand'Mare</=>
- 451 : Voisins-le-Bretonneux Collège Hélène Boucher <=> Saint-Rémy-lès-Chevreuse Gare</=>
- 452 : Voisins-le-Bretonneux La Bretonnière <=> Voisins-le-Bretonneux Collège Champollion</=>
- 453 : Guyancourt E. Viollet-le-Duc <=> Saint-Rémy-lès-Chevreuse Gare</=>
- 454 : Montigny-le-Bretonneux Collège St-François d'Assise <=> Saint-Rémy-lès-Chevreuse Gare</=>
- 455 : Guyancourt Bouviers <=> Montigny-le-Bretonneux Collège St-François d'Assise</=>
- 456 : Voisins-le-Bretonneux Collège Champollion <=> Buc Franco-Allemand high school</=>
- 457 : Chateaufort Place / Magny-les-Hameaux Z.A du Bois des Roches <=> Montigny-le-Bretonneux Collège St-François d'Assise</=>
- 458 : Montigny-le-Bretonneux Saint-Quentin Gare <=> Montigny-le-Bretonneux Saint-Quentin-Gare</=>
- AQ: Collège Apollinaire <=> Léon Blun</=>
- BL: Apollinaire <=> Lamartine</=> College
- CSP: La <=> Chaîne Collège La Clef Saint Pierre</=>
- JV: Lycée Jean Vilar <=> Mare aux Saules</=>
- TG: Rond-Point de Grignon <=> Collège Apollinaire</=>