More flow in the station: how passenger analyses improve the Zurich HB SZU
The Sihltal Zürich Uetliberg Bahn (SZU) is expanding its underground station in Zürich HB - with Basler & Hofmann at its side as general planner. Our experts laid important foundations for the planning at an early stage with passenger flow studies. In an interview with SZU, Elena Odermatt and Martin Ellwanger report on how they calculate passenger flows and help to make railway stations fit for the future.
The number of passengers at Zurich Main Station (HB) is growing and growing. The 30-year-old Zurich HB SZU underground station with tracks 21/22 is already one of the busiest railway stations in the canton of Zurich. The SZU is therefore reacting and expanding its underground station at the main station. At the same time, it is creating the conditions for accessibility - in accordance with the Disability Discrimination Act (BehiG) - and increasing user-friendliness.
How people move around the station
How do people move around the station - and where do they get stuck? Between 2018 and 2025, Elena Odermatt and Martin Ellwanger carried out comprehensive people flow studies for Zurich Main Station SZU. The environmental engineer and the civil engineer analyzed how many people move and stay where and when. They made suggestions on how to improve the routes in the underground station and the quality of stay. Now, at the beginning of July 2025, construction work will begin.
In an interview with SZU, the two explain how pedestrian traffic flows and layout optimizations can be analysed, where typical bottlenecks occur - and why underground railway stations pose different challenges to those above ground. Orientation, site development and space are key issues. Also interesting: Her construction on how the capacity of railway stations can be improved with clever architecture and good routing.
Read the full interview with Elena Odermatt and Martin Ellwanger on the SZU website.
Overall planning mandate for the expansion of the railway stations
As general planner, Basler & Hofmann is assuming overall responsibility for the planning of the "Zurich HB SZU extension". We are planning the project and coordinating all consultants - from track and platform construction to building services and environmental planning. "Together with our sub-planners, we cover all planning disciplines. Basler & Hofmann's share of the work is around 70 percent," says overall project management Marius Ammann.
Construction work began at the start of July. In the first construction phase - until spring 2026 - the SZU platform will be extended at the rear towards the Limmat and a new staircase to Shopville will be built.
The main work will take place from May to October 2026, during which time the Zurich HB SZU underground station will be completely closed for 24 weeks (see SZU media release). "We are optimizing the two existing entrances to the platform. In addition, the platform will be raised along its entire length to ensure barrier-free boarding and alighting of trains in future," says Ammann.
The people flow studies have helped to improve the planning in a targeted manner. "They provided important input for the existing entrances in particular," says Ammann. For example, the studies provided information on the ideal location of the entrances and how the furniture on the platform could be improved.