The highest elevation on the section between Nesslau-Neu St. Johann and St. Gallen is reached near Degersheim (798.7 metres (2,620 ft) a.s.l.).

The network is mostly a single-track railway, with intermittent double-tracks (9.84 kilometres (6.11 mi) in total) present in sections where trains cross regularly.

The 8.6 kilometres (5.3 mi) long Ricken Tunnel on the Uznach–Wattwil line, used by the SOB operated Voralpen Express and S4 service of St. Gallen S-Bahn, belongs to Swiss Federal Railways (SBB CFF FFS).

Until 2019, nine second class control cars (BDt) were used for the Voralpen-Express sets with Re 456, Re 446 or Re 420 (the latter occasionally leased from SBB-CFF-FFS) locomotives.

The NPZ sets were later replaced by Stadler FLIRT EMUs (four-car-sets), delivered between 2007 and 2013 (RABe 526 041-526 063).

The latter were painted in the most recent SOB livery: silver, with red window band, and light gray doors.

Due to the clock-face scheduling, the Swiss rail network offers passengers timely connections at most railway stations.

From 1992 to 2013, Voralpen-Express (English: "Prealps Express") was jointly operated with the Swiss Federal Railways (SBB CFF FFS), and it continued as a regional train between St. Gallen and Romanshorn.

IR Voralpen-Express: Luzern – St. Gallen Luzern – Luzern Verkehrshaus – Meggen Zentrum – Küssnacht am Rigi – Arth-Goldau – Rothenthurm – Biberbrugg – Pfäffikon SZ – Rapperswil – Uznach – Wattwil – Herisau – St. Gallen Voralpen-Express runs mainly on tracks of the SOB network but uses tracks owned by Swiss Federal Railways between Lucerne and Arth-Goldau, and between Rapperswil and Wattwil (including the 8.6 kilometres (5.3 mi) long Ricken Tunnel on the Uznach–Wattwil line).

Treno Gottardo (Italian for "Gotthard train") is jointly operated by SOB and SBB CFF FFS and runs entirely on the network owned by the latter.

[4] Basel SBB – Locarno Basel SBB – Olten – Luzern – Arth-Goldau – Schwyz – Brunnen – Flüelen – Erstfeld – Göschenen – Airolo – Ambri-Piotta – Faido – Lavorgo – Bodio TI – Biasca – Castione-Arbedo – Bellinzona – Cadenazzo – Tenero – Locarno Zürich HB – Locarno Zürich HB – Zug – Arth-Goldau – Schwyz – Brunnen – Flüelen – Erstfeld – Göschenen – Airolo – Ambri-Piotta – Faido – Lavorgo – Bodio TI – Biasca – Castione-Arbedo – Bellinzona – Cadenazzo – Tenero – Locarno Treno Gottardo follows the scenic route of the Gotthard Railway.

All InterCity and EuroCity trains instead use the 57.09 kilometres (35.47 mi) long Gotthard Base Tunnel since its opening in 2016.

Aare Linth is operated by SOB in cooperation with SBB CFF FFS; it runs entirely on the Swiss Federal Railways network.

Stadler "Traverso" trainsets operate on this InterRegio line except during rush hour, when higher-capacity rolling stock of SBB CFF FFS is used.

Bern – Chur Bern – Burgdorf – Herzogenbuchsee – Langenthal – Olten – Zürich Altstetten – Zürich HB – Thalwil – Wädenswil – Pfäffikon SZ – Siebnen-Wangen – Ziegelbrücke – Unterterzen – Walenstadt – Sargans – Bad Ragaz – Maienfeld – Landquart – Chur In December 2024, the new named train Alpenrhein-Express began operations using Stadler "Traverso" EMUs.

[7] St. Gallen – Chur St. Gallen – Rorschach – St. Margrethen – Heerbrugg – Altstätten SG – Buchs SG – Sargans – Bad Ragaz – Maienfeld – Landquart – Chur As of the December 2023 timetable change,[update] Südostbahn (SOB) operates the following S-Bahn services in Central and Eastern Switzerland:[8]