A subway route to Berlin-Brandenburg Airport has been discussed in Berlin for a long time. This is supported by most politicians, but opinions differ widely when it comes to the question of who should bear the construction costs beyond the city limits.

The German capital airport can currently be reached by both train and bus. However, there are increasing voices calling for the U7 subway line to be extended to the airport, which is located in the state of Brandenburg. A so-called cost-benefit study has now been commissioned. This is intended to evaluate whether the project makes sense from a financial perspective or not.

However, it is already clear that Berlin does not want to or cannot cover the construction costs outside of its own federal state alone. It is hoped that the federal government will provide financial support, although a positive cost-benefit study is necessary for this. It is also demanded that the federal state of Brandenburg should participate, as it would also benefit from any additional public transport offerings.

Those responsible for the project do not currently want to comment on specific construction costs. Last year, Berlin Senator Franziska Giffey (SPD) gave an estimate of around 890 million euros. She assumed that the federal government would issue a positive funding decision by the end of 2023. However, this has not yet happened because the necessary study has not yet been carried out.

It remains to be seen to what extent a possible extension of the U7 would actually be an improvement for BER passengers. In any case, numerous stops would then be accessible from Berlin-Brandenburg Airport without having to change trains. However, it can be assumed that the travel time could be longer in direct comparison with the express trains to the city center.