Answers to the most frequently asked questions about the new S4

The S4 project between Altona and Bad Oldesloe

  • By constructing two new tracks specifically for the S4, we are ensuring that the new line will not be affected by any other rail services. This will lead to fewer delays and provide passengers with a fast, direct connection between Hamburg and Schleswig-Holstein.
  • The new stations will provide better links to other lines and cut journey times, as passengers will be able to get to many destinations in Hamburg without changing trains at the city's main station.
  • Capacity pressures will be eased at Hamburg's main station. The S4 will use the local transport network's S-Bahn tracks, thereby freeing up space for long-distance trains.
  • Getting to Hamburg Airport will be easier: at Hasselbrook, many passengers will only have to go to the other side of the platform to catch the S1.
  • To meet continuously rising demand for local transport, the S4 line will use modern S-Bahn trains that are completely barrier-free for easy access.
  • Drivers and pedestrians won't have to wait at level crossings anymore because most of these will either be removed completely or be replaced by bridges and tunnels. This will significantly increase safety.

The planning approval procedure for the first section (Hasselbrook to Luetkensallee) began in September 2016. We received the planning approval decision, i.e. the building permit for the first section, in August 2020. The preparatory construction measures then began on 9 November 2020. The official ground-breaking ceremony took place on 10 May 2021. At the end of 2021, the Federal Administrative Court dismissed all appeals received - the decision is therefore final.

We submitted the documents for the second section (Luetkensallee to the Free and Hanseatic City of Hamburg/Schleswig-Holstein state border) to the Federal Railway Authority at the end of September 2017, and the public display took place in November 2019. The amended planning approval documents were displayed from mid-April to mid-May 2023. The objection period ran until mid-June 2023. A display of the second plan amendment took place in December 2023. The consultation meeting for all documents and amendments took place from April 22 to 24, 2024. 

DB InfraGO AG submitted the application for planning approval/building permission for the third section (Free and Hanseatic City of Hamburg/Schleswig-Holstein state border to Ahrensburg-Gartenholz) to the Federal Railway Authority in Hamburg at the end of July 2017. The documents were on display from the end of September to the end of October 2023. Objections and comments on the documents could be submitted until the beginning of November. Objection management is currently underway.

After all objections have been weighed up and the hearing procedure has been completed, the planning approval decision is issued for the other sections.

Fares will not automatically go up because of the S4. Ticket prices are not directly linked to the project. Instead, they are calculated using various indexes and inflation rates, and they only increase when the local parliament passes legislation based on proposals from the relevant transport association. In the S4's case, this is hvv.

Two regional services serve the route between Hamburg and Lübeck: RE 8 and RB 81. Trains stop at Ahrensburg, Bad Oldesloe and Reinfeld. The RB 81 service also connects Hamburg and Bad Oldesloe, stopping at Hasselbrook, Wandsbek, Tonndorf, Rahlstedt, Ahrensburg, Ahrensburg-Gartenholz, Bargteheide and Kupfermühle.

The S4 will replace the RB 81.

New dual-system trains (ET 490 series) will operate on the S4 line. They can be powered by the overhead line as well as the third rail. 72 new ET 490 trains have been added to Hamburg's S-Bahn fleet since December 2018. These vehicles have been running on the S21 line and are occasionally also in service on the S3 line.

The new vehicles have an eye-catching design. The nose of the trains looks like a giant silver H as a reference to Hamburg, while a closer look reveals countless other innovations features. The carriages are all connected to form a single, undivided interior, something that enhances people's sense of safety on board. Air conditioning and modern passenger information screens are also present. Each train has a total of 190 seats and 280 standing places, in addition to multi-purpose areas for wheelchairs, prams and pushchairs. S-Bahn trains do not have toilets.

Passengers will be able to transport bikes on the S4, just like on all S-Bahn services in Hamburg and Schleswig-Holstein.


As things currently stand, there will be an S4 train to Ahrensburg every 10 minutes, to Bargteheide every 20 minutes and to Bad Oldesloe every 60 minutes during peak times.

The door mechanism on S-Bahn trains will work faster, thereby cutting the length of time spent at stations. Journeys between Ahrensburg and Hamburg's main station will take slightly longer. One regional train will continue to operate on this stretch. Passengers will need less time to get to other destinations (e. g. the airport) because it will be easier to change between different services or because they will no longer need to change at all (e. g. when travelling from Rahlstedt to Altona). Differences between trains' acceleration capacities will not have any impact on journey times.

The station is extremely busy and operating at maximum capacity. The S4 will use the station's S-Bahn tracks and replace some 120 trains that run between Hamburg and its northeastern hinterland every day. This will free up track capacity that can then be allotted to long-distance and regional trains.

The preparatory construction measures for the first section began on November 9, 2020, with the official ground-breaking ceremony taking place on May 10, 2021.

In principle, each of the three sections will undergo its own planning approval procedure lasting approx. 30 months. The construction period for all sections is expected to take around 7 years.

The partial commissioning of the S-Bahn line S4 to Rahlstedt is planned for the timetable change in December 2027 and the full commissioning of the S4 to Bad Oldesloe is planned for the timetable change in December 2029.

Many people rely on an efficient local transport service to get between Hamburg and Schleswig-Holstein every day. The fact is underlined by the growth in passenger numbers in the region: between 2000 and 2010 alone, demand for regional transport between Hamburg, Ahrensburg and Bad Oldesloe increased by 50%.

No. A higher number of freight trains the Lübeck-Hamburg line is not connected to the construction of the S4. The S4 is a local transport project, and it will reduce pressure on the current long-distance line because it will replace the regional trains that operate between Lübeck and Hamburg today.

However, our plans do factor in an increase in train numbers – for example, we have considered this in our noise studies and rail operation analyses.

This growth is largely due to Fehmarnbelt Fixed Link, which will open in 2029 at the earliest. We expect that Denmark will complete its work on the Fehmarnbelt tunnel by that date.

Structures and construction work

The new S-Bahn line from Altona in Hamburg to Bad Oldesloe has a total length of 35.9 kilometres. Following a decision by Hamburg and Schleswig-Holstein at the end of 2015, the project comprises 17 kilometres of new double track between Hasselbrook and Ahrensburg and a new single-track connection from Ahrensburg to Ahrensburg-Gartenholz. About one third of the new line (approx. 7 kilometres) is in Schleswig-Holstein while two thirds (approx. 13 kilometres) is in Hamburg. Four new stops will be built on the section in Hamburg: Wandsbek Rathaus, Bovestrasse, Holstenhofweg and Pulverhof. There will be one new stop in Schleswig-Holstein: Ahrensburg-West. The S4 will continue to Bad Oldesloe using the track that exists today.

Yes. When we were looking for the best solution, we assessed different proposals that incorporated a range of alternative parameters: costs, advantages, environmental factors, urban planning, technical feasibility, public acceptance and the evolution of traffic over time. Early in the process, we decided to select a route that would have the least possible impact on people's private property and green spaces.

In a rail operations analysis, this option scored higher than proposals for an alternative route via Lüneburg and Büchen or positioning the line next to the A1 motorway. This kind of analysis aims to identify a good balance between the new infrastructure and the range of services we want to provide. These need to be economically viable and scheduled so trains operate on a reliable basis.

The S4's present route was the best one in terms of sustainability and environmental impact.

The preparatory construction measures in planning approval section 1 (Hasselbrook - Luetkensallee) began on November 9, 2020. The subsequent main construction measures (e.g. new construction of bridges, stations and noise barriers) started on May 10, 2021 with the official ground-breaking ceremony.

Planning approval for sections 2 and 3 is still pending.

We have started the first batch of preparatory measures (see above) at various sites in planning approval section 1. Planning approval for sections 2 and 3 is still pending.

Our aim is to minimise the work's impact on local residents. This is a key aspect of our construction process plans, which look at how we could shield residents and describe the associated measures we will undertake. The decision for planning approval section 1 contains various requirements and regulations that the project team and our construction companies must adhere to so local residents and the environment are protected. The continuous measurement of construction noise is just one of these requirements.

It goes without saying that we will provide people with advance information about our work and its impact.

A certain level of disruption is unavoidable given the scale of this project. However, we hope that line closures can be restricted to weekends and nighttime. It is very important to us that commuter services can operate as smoothly as possible during peak times. If there are closures, we will guarantee that the public can still rely on public transport, for example in the form of rail replacement connections.

We will coordinate construction activities (e. g. work on bridges) with the relevant authorities. Work will mainly take place during the day and will sometimes be loud. Work will take place at weekends, on public holidays or at night only in exceptional situations, and we will always announce these cases in good time.

These are two different projects with separate planning activities, legal procedures and approval processes.

The S4 is a local transport project. It is designed to relieve congestion at Hamburg's main station and improve regional transport.

The Fehmarnbelt Fixed Link has a variety of aims, such as halving journey times between Hamburg and Copenhagen from just under 5 hours to 2:30 hours.  The German government's transport infrastructure plan designates both projects as priorities.

Only the platforms at Kupfermühle station will have to meet special interoperability requirements for ensuring the smooth transition between different technical systems. Interoperability covers a range of issues, such as the height of platforms, which is important for accessibility. The tracks of the trans-European network run though Kupfermühle, and this has implications for its platforms. The other stations only feature S-Bahn tracks, and these stops will be barrier-free in line with national regulations.


The project costs amount to EUR 1.439 billion* ¹. The framework financing agreement was signed on 29 November 2019.

* ¹ EUR 1.846 billion when nominalised. This figure includes all potential risks.

The S4 is a joint undertaking between the states of Schleswig-Holstein and Hamburg. DB InfraGO AG was commissioned with planning and operations.

On 29 November 2019, the framework agreement for financing was signed by the premier of the state of Hamburg Peter Tschentscher, the premier of the state of Schleswig-Holstein Daniel Günther, Germany's transport minister Andreas Scheuer and Deutsche Bahn's CEO Dr Richard Lutz. This agreement guarantees funding from the federal government. Detailed information is available in the Financing section.

Yes. EU money is available for the S4 project due to the importance of the Hamburg-Lübeck route for transport planning strategies on a European level. Between 2015 and 2023, the project team will submit several funding applications, with the EU covering 50% of planning costs in each case.

Protecting people and the environment

As with so many things in life, the S4 has its supporters and opponents. Its potential to improve local transport is widely recognised by the public.

Deutsche Bahn always relies on dialogue when dealing with local residents. The S4 team is there for anyone who wants to discuss an issue, be it in the form of a citizens' consultation or at an infobus event. We organise information evenings, attend trade fairs and give presentations on all kinds of topics. The S4 team provides transparent information about our plans and is always available for questions and discussions.

The dialogue section of this website contains the details of upcoming events.

Additional fascinating insights are available on the page dedicated to the latest news and in our project diary. You can also contact the S4 project team by e-mail at S4 (at) or via our hotline at +49 (0) 40/3918-2161.

Another source of information is our newsletter, which we publish regularly. Why not sign up for it? Click here to register: newsletter.

Our current plans feature 45 kilometres of noise barriers at the locations marked on our route map. Barriers positioned to the north and south of the line will be up to 6 metres high. We will also install a 4-metre high noise barrier between the S-Bahn and long-distance tracks.

The noise emissions study was carried out in accordance with the relevant legislation (16th ordinance for the implementation of Germany's pollution control act), which regulates how to perform acoustic calculations in the event of significant changes to rail lines. It also specifies immission limits for the different activities that take place within a given area.

We will also follow the environmental guidelines of the Federal Railway Authority.  The noise emissions study compares different types of active noise protection (e. g. noise barriers of different heights, or the specially monitored track).

We found that we can achieve the most sustainable form of active noise control by installing lateral barriers of up to 6 metres in height and using 4-metre central barriers on certain sections of track. If we still fail to comply with all statutory noise limits despite everything, local residents are entitled to what is known as passive noise control.

It is important to remember that these passive measures are available only for rooms that are legally designated as requiring protection. The planning approval decision describes residents' entitlements. Click here for a definition of active and passive noise control measures, in addition to charts and illustrations that describe how noise levels will change.

People's wellbeing is of central important to DB InfraGO AG. For this reason, our construction work will be carried out carefully so that noise emissions are reduced as much as possible.

During construction, our contractors make use of state-of-the-art, low-noise building methods and machinery as part of our focus on keeping noise as low as possible. In addition, our construction noise officer deals specifically with issues relating to noise at building sites. Anyone who wants to address a problem can simply get in touch with them.

Again, sensitivity and responsibility will be the hallmarks of our actions in this context. Producing a comprehensive environmental report was part of the preliminary design stage, and we incorporated the results into our planning activities early on. Several assessments studied the project's environmental impact, looking at issues such as environmental compatibility, effects on the landscape, wildlife and plants, protected species, groundwater, construction noise, operational noise, light levels and electromagnetic compatibility. We will work to minimise the S4's impact on flora, fauna, soil, water, climate, air, landscape, townscape and human wellbeing during both construction and operation.

To achieve this, the project team is in constant contact with conservation organisations and associations. Further information is available in the Nature section.

Yes. Unfortunately, there is no way to avoid removing trees growing at sites that we will use for a limited period (e. g. areas adjacent to building sites and access roads) or at locations that will be given over to the S4's infrastructure (e. g. new tracks, noise barriers).

When we were planning the project, we worked to keep the impact on local plant life to a minimum in accordance with Germany's conservation legislation.

The environmental impact mitigation plan contains the details of what trees, hedges, etc. we will cut back or remove in the course of the project.

The mitigation plan also provides information about the overall impact of these activities and about our compensatory measures. We will ensure that environmental supervision is part of our work. This team monitors the impact of our activities and ensure that compensatory measures are implemented in line with legislation.

Rail is one of the safest modes of transport there is, for both freight and passengers. During construction, we will assess and optimise safety measures.

Transporting freight by rail has several advantages:

  • Trains are guided by their tracks, which provide an additional layer of control.
  • Safety features ensure that operators can maintain a set distance between trains. In contrast, motorists have to constantly gauge and adjust their distance from other vehicles when on the road.
  • Rail technology can be used so the risk of human error is minimised.
10.06.2024Construction site camera on section 1