Never open ports to the internet unless you want everybody to see it. Always use VPN to access your selfhosted stuff. If you’ve got a lot of VPN connections to set up, try generating a QR code for the connection. Makes it a bit faster to setup the client.

The sort of people that ride the bus and train is most of the population in the EU and a lot of other countries.

Reduce 27 lanes to 4 lanes with bus priority lanes and put people on a bus. Thats 27 cars with 5 people in roughly 2 buses with ~50 people.