Operations
The R3 operates every hour between and , using the western end of the Simplon line. The R3 makes a limited number of stops between and Bex. The R3 is paired with the R4 between and Bex, providing half-hourly service. Both the R3 and R4 provide limited service beyond Bex to .History
The "first" S3 was one of the six original lines of the RER Vaud, then called the Vaud Express Network (, REV), when that system was established in December 2004. It ran hourly between Allaman and , on the Simplon line. With the December 2020 timetable change, the S3 was cut back to Lausanne, with the S5 taking over the Lausanne–Villeneuve service. The RER Vaud lines were substantially reorganized for the December 2022 timetable change. The "new" S3 was a combination of the former S2 and S5, making local stops on the Simplon line between Vallorbe and Aigle, with limited service from Aigle to St-Maurice. On 10 December 2023, all RER Vaud lines were renamed as "R" and a number, instead of "S". In December 2024, the R3 was extended from to , the service from Bex to St-Maurice was taken over by the RE33 service.References
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