S20 (RER Fribourg)
The S20 is a railway service of RER Fribourg that provides hourly service between  and , in the Swiss cantons of Neuchâtel and Freiburg, respectively. The S20 is extended to  on weekdays. Transports publics Fribourgeois operates the service. Operations 
The S20 runs hourly between  and . On weekdays it continues to . It uses the western end of the Bern–Neuchâtel line, the entirety of the Fribourg–Ins line, and a portion of the Lausanne–Bern line. It is paired with the S21 between  and Romont, providing half-hourly service. History 
RER Fribourg introduced the S20 designation on 14 December 2014 for an hourly service between  and Neuchâtel. In December 2017, the S21, previously a rush-hour service between Fribourg and , was re-routed to run between Fribourg and Ins and rescheduled for hourly service on weekdays, increasing the service level between Fribourg and Ins to half-hourly on weekdays. With the December 2021 timetable change, both the S20 and S21 were extended south from Fribourg to Romont, replacing the S40. The S21 began running on weekends with this change, while the S20 operated between Fribourg and Romont on weekdays only. References

External links 
 2022 timetable: Neuchâtel–Fribourg and Fribourg–Romont

RER Fribourg lines
Transport in the canton of Bern
Transport in the canton of Fribourg
Transport in the canton of Neuchâtel
Transport in the canton of Vaud