The new S4

The S4 project from Hamburg to Bad Oldesloe

The S4 is on its way! Connecting Hamburg and Bad Oldesloe.

DB InfraGO AG

Hintergrund-Ebene der Zuganimation in der StadtAnimierter ZugVordergrund-Ebene der Zuganimation in der Stadt
Latest NewsThe resident information for the construction work in July 2025 is online.More information

Opening hours in our S4-Info Train

Thursdays, 3.30 – 5.30 p.m.
Tuesdays for groups by previous appointment at S4 (at) deutschebahn.com 

More convenient, more efficient and more punctual 

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 

In-depth information about the planning process and our construction work

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. 

Our project diary

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!

Friday, 20. June 2025

The S4 as a lighthouse project at the most important public transport event

The well-attended S4 stand at the UITP Summit 2025

DB InfraGO AG

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.

Friday, 23. May 2025

A look behind the scenes – discover the S4 construction site!

Impressions of the construction site tour

DB InfraGO AG

Discover the construction site of the S4 S-Bahn line on a guided tour!

Would you like to experience firsthand how the new S4 S-Bahn line is being built? Then take advantage of this opportunity and secure your spot on one of our guided construction site tours!

Tuesday, 18. February 2025

Highlights 2024

Baustellen Fortschritt 2024

DB InfraGO AG

Progress in the S4-Project in 2024.

And that's how quickly time flies! We can now look back on a year full of milestones and highlights that we achieved through hard work and passion. Of course there were also hurdles that we had to overcome, but let's take a look together at everything we have achieved.

14.07.2025Construction site camera on section 1