The sign you referenced, the Hydrogen refueling station, indicates the location of a facility where hydrogen fuel is available for vehicles powered by hydrogen fuel cells. This sign is primarily intended for drivers of hydrogen-powered vehicles, guiding them to places where they can refuel.

In Germany, the use of hydrogen as an alternative fuel is encouraged as part of efforts to promote sustainable mobility and reduce emissions. If you see this sign while driving, it means you are approaching a hydrogen refueling station, and you should follow any additional guidance related to accessing the facility.

If you have any other questions about traffic rules or signs, feel free to ask!