The S4 project from Hamburg to Bad Oldesloe
The S4 is on its way! Connecting Hamburg and Bad Oldesloe.
Opening hours in our S4-Info Train
Every first Thursday of the month, 3:30 p.m. – 5:30 p.m.
Tuesdays for groups by previous appointment at S4 (at) deutschebahn.com
The S4 information train will be closed for the winter from December 4, 2025, to January 29, 2026.
Passenger numbers on northern German rail services have risen sharply in recent years, and the necessary mobility turnaround is expected to lead to even more people switching to rail in the future. To make this possible, the infrastructure at the Hamburg hub is being massively expanded.
Passenger numbers have also been rising steadily for years on regional services between Hamburg, Ahrensburg and Bad Oldesloe. We are responding by constructing the S4. This new S-Bahn line will provide the region's inhabitants with better local transport between Hamburg and Bad Oldesloe. Some 250,000 people will benefit from this new service.
Opportunities and Benefits Financing
Protecting flora and fauna is of vital importance to Deutsche Bahn and all of our project partners. Together, we have designed a range of measures along the route that will safeguard water and soil quality as well as protect the existing landscape. We are working to ensure that the new S-Bahn does not pose a threat to endangered species such as the great crested newt.
The plans for the S4 line include comprehensive active and passive noise mitigation measures, such as trackside barriers and a host of other features. Our website contains detailed information about these and about how our work will change noise levels along the line.
We want you to have the most comprehensive information possible about the S4. What is the current status of the project plans? When will construction work start? And what impact will the project have on people and nature? We have identified the key questions about the project and now have the answers for you.
20 kilometres of existing line from Hasselbrook to Ahrensburg-Gartenholz will be upgraded for the new S-Bahn service. The project consists of three sections. Each of them has its own specific planning procedure, which means separate approval is necessary for every section.
There's a lot happening when it comes to the planning and construction of the new S4. Our project diary keeps track of the latest developments and follows how the project is going. Members of the project team also provide details about their work so you know more about what's happening in the background. It's a mine of interesting information. Enjoy!
Tuesday, 14. October 2025
On September 19, 2025, the nationwide Rail Day took place across Germany. Since its launch in 2022, the Rail Day has highlighted the rail industry’s diversity, opened doors to career paths, and showcased the future of rail technology in action.
Friday, 5. September 2025
On Friday, September 19, 2025, we cordially invite you to the nationwide Rail Day. The construction site of the new S4 S-Bahn line will open its doors for two exclusive tours – a special experience for anyone interested in modern infrastructure and sustainable mobility.
Friday, 20. June 2025
The well-attended S4 stand at the UITP Summit
The UITP Summit took place in Hamburg from 15 - 18 June 2025. This is considered the world's largest event in the field of sustainable mobility. We are delighted to have been chosen by Anjes Tjarks (Senator for Transport and Mobility Transition of the Hanseatic City of Hamburg) as a lighthouse project to represent the city of Hamburg and communicate the importance of the S4 project to experts from over 100 countries.
