Special Tunnel attributes
Some Tunnels need very special attributes for emergency issues:
- Escape doors / Fluchttüren
- Safety niches / Schutznischen
- Connections to other Tunnel tubes / Verbindung zu benachbarter Tunnelröhre
- Connections to Emergency shafts / Verbindung zu einem Notausstiegsschacht
There are special radio systems (channels, repeater location), that work inside the tunnel.
There may be more than one track in the tube, we have to restructure the tunnel element to model a crossover inside a tunnel.
How about country borders in the tunnel? There have to be different mileages for one tunnel.