Outside Connections not Working
Symptoms
Outside connections not working properly; some examples:
Vehicles not entering by highway
Vehicles aren't using some, but not all highway connections
Vehicles using highways but nobody moves in to city (see also: Population stuck at 0)
No cargo vehicles entering the city (see also: Vehicles not spawning)
Aircraft not entering city
Aircraft enter city, but won't land
Ships not using harbours
Inter-city trains not spawning
Inter-city trains not stopping at stations
Causes
There's lots of things that can break outside connections, let's just skip to solutions...
Solutions
Incompatible mods
These mods are known to cause issues:
Cargo Info - prevents vehicles spawning on highways, also causes Simulation error Array index is out of range error.
81 Tiles (all variants) - doesn't currently support intercity buses outside central 25 tile area
Quistar is working on new implementation of 81 Tiles mod that might fix this as part of his Extended Managers Library
General outside connection issues
Outside connections must have green arrows at edge of map:
If arrows are missing, the connection is broken...
Roads: Only highway roads can be used by default
Use Any Road Outside Connections to overcome that limitation
Zoned roads don't work; use Zoning Adjuster to disable zoning while placing the outside connection.
Two-way roads break intercity buses; see: Intercity Buses not Working
Rail: Some custom rail tracks don't work as outside connections
The outside connection must be made from special station track
If you connect vanilla train track to outside, game automatically replaces with station track
Custom tracks (workshop assets) probably won't work; replace with few segments of vanilla track
If station track segment is too small, use Move It mod to stretch it, or bulldoze and rebuild
Ferry: These can not be used for outside connections (use ship harbours instead)
Blimps, Helicopter, Air tours: These can not be used for outside connections (use airports instead)
Tram, monorail and metro: These can not be used for outside connections (use train stations instead)
Connections showing "no power" or "no water" notifications at edge of map are broken:
This can happen on any type of outside connection (for example: Aircraft, Highways)
Often caused by old Ploppable RICO mod; replace it with newer Ploppable RICO Revisited mod.
Too many connections:
Each type of connection (road, rail, aircraft, ships) has a limit on how many connections of that type can exist
Use Unlimited Outside Connections to overcome that limitation
Did you create your own connections?
If so, it sometimes takes a while for the game to start using them
Sometimes you might need to save, quit to desktop, then reload for changes to take effect
General station / port / hub issues
The station must be connected to your city by road
Some stations (like this) require pedestrian path connection instead
Some stations are designed to work more effectively when connected to train (e.g. Cargo harbours) or metro (e.g. International airport)
Broken workshop assets:
Stations must contain spawn points to function correctly
Use Spawn Points Fix or Building Spawn Points to repair
Passenger stations:
Click the station, and on the info panel you'll see an Inter-city option
To get similar option on bus stations, use Intercity Bus Control mod
If you want inter-city vehicles to use that station, you must enable the option
Highways
In addition to general issues listed above, check for these issues:
Broken connection between highways and your city roads:
Most highways are two separate 1-way roads; one incoming and one outgoing
Make sure both connect to your city road network
If in doubt, connect both highway roads with a bit of 2-way normal road and see if that helps
One way roads preventing vehicles from reaching their destination:
Unless you know how to properly use one-way roads, it's best to avoid them.
Activate the road building tool, and you'll see white arrows on any one-way roads - replace them with 2-way roads
Trains
In addition to general issues listed earlier, check for these issues:
One-way tracks preventing vehicles from reaching their destination:
Unless you know how to properly use one-way tracks, it's best to avoid them.
Activate the track building tool, and you'll see white arrows on any one-way tracks - replace them with 2-way tracks
Outside connection platform not connected:
Inter-city trains always use the same platform, chosen by the game
If that platform isn't connected to outside connection the trains can't use the station
Simple solution: Connect all station tracks to the outside connection
Once you see which platform they use, you can disconnect the others if desired
Passenger Ships
In addition to general issues listed earlier, check for these issues:
Not connected to shipping lane:
When placing harbour, you should see a purple line extending out in to the sea
If that line isn't there then the harbour isn't connected to a ship lane and no ships can use it
Broken ship routes:
They can be hard to spot (because it's a dashed line, not a solid line)
Sharp bends or gaps in the route can cause problems
Use More Network Stuff to repair routes if required
Aircraft
In addition to general issues listed earlier, check for these issues:
Not connected to aircraft route:
When placing airports, you will see a warning if the airport isn't in range of an aircraft route
If the airport can't connect to the route, planes can't use the airport
Broken runways or taxiways
The aeroplane AI is easily confused
Used curved paths, not sharp corners (jumbo jets don't handle corners very well)
Runways and taxiways are usually (always?) one-way - make sure planes can go from runway to terminal and back to runway again
Broken aircraft routes:
They can be hard to spot (because it's a dashed line, not a solid line)
Sharp bends or gaps in the route can cause problems
Use More Network Stuff to repair routes if required
Was it Fixed?
If not, try:
Other issues? See: 👉 Troubleshooting