Mägenwil loop boosts capacity between Aarau and Zürich

The roughly 1 km new connecting line (the "Mägenwil loop") links the Heitersberg line (Aarau–Killwangen-Spreitenbach) with the Southern line (Brugg–Othmarsingen) between Mägenwil and Birr in canton Aargau. It lets Basel–Zürich freight trains bypass the congested Heitersberg bottleneck, freeing up capacity for a continuous half-hourly S11 service between Aarau and Zürich. The roughly CHF 135 million project, funded through the federal rail infrastructure fund, has been operational since the December 10, 2023 timetable change.