The Swedish Data Protection Authority Datainspektionen has issued guidance on surveillance in public transportation.

Key Takeaways:

• In order for the camera surveillance to be considered permitted, the need to monitor must outweigh the intrusion it entails for individuals to be monitored in public transport.
• In several places in public transport where individuals stay for a longer period of time, for example in waiting rooms or on bus lines with a long average travel time, you must have compelling reasons for the surveillance to be legal.
• You must inform about the surveillance through clear signage or in another effective way. You must also inform about who is responsible for the surveillance and how to get in touch with them.
• For camera surveillance for crime prevention purposes, storage of video is normally permitted. However, the video may not be saved longer than necessary. Sound is generally not allowed to be recorded.
• Recorded material must be protected from unauthorized use. The person conducting the surveillance must decide which persons need access to the recorded material, and ensure that no one other than them has access to the material.

Read the full details from the Swedish Data Protection Authority