Stuttgart 21

Stuttgart 21 (for 21st century) is a major railway and urban development project in Stuttgart, Germany, that is replacing the surface railway lines with tunnels. It is a part of the Stuttgart–Augsburg new and upgraded railway and the Main Line for Europe (Paris—Vienna) within the framework of the Trans-European Networks. Its core is a renewed underground Stuttgart Hauptbahnhof, among some 57 kilometres (35 miles) of new railways, including some 30 kilometres (19 miles) of tunnels and 25 kilometres (16 miles) of high-speed lines. The project was highly controversial up to 2010, and still is since, due to destruction of old structures, large area construction works, high costs, and ongoing duration. The still operational central terminus station, with 16 surface platforms shortened and with impeded access due to the large construction pit, is going to be replaced by an underground through-station with only 8 platforms. The project was officially announced in April 1994. Construction work began on 2 February 2010. In March 2013, total costs were officially estimated at €6.5 billion, the previous estimate being €4.5 billion in 2009. In March 2022, Deutsche Bahn estimated the total cost at €9.15 billion. Heated debate ensued on a broad range of issues, including the relative costs and benefits, geological and environmental concerns, as well as performance issues. In 2019, operations had been expected to start in December 2025, delayed from the initial estimation of 2019 (made in 2010). In 2024, the opening date for main elements of the project was delayed again, to December 2026. In 2025, the planned opening date of December 2026 was canceled, officially due to technical issues with the new signaling system. By June 2026, a Deutsche Bahn audit found the 2026 commissioning date to be unrealistic. The new Stuttgart Hauptbahnhof is scheduled to open in December 2031, with...