From time to time when playing Mini Metro you’ll be offered an Interchange as one of your weekly upgrades. Depending on how you use them, they can either be incredibly useful or a waste of a pick. In order to make the optimum choice you need to understand what Interchanges do and how they work.
What is an Interchange?
An Interchange in mini Metro is a station upgrade. You can add it to a single station of your choice at any time. The station’s icon is then slightly enlarged to indicate the presence of the Interchange. (Note that stations can’t be upgraded more than once, so you can’t add an Interchange to a station that already has one. Nor can you remove an Interchange or move it from one station to another, they’re permanent.)
If you’re like me, you might have trouble at first working out how exactly to add the Interchange – you need to drag it from your ‘extras’ section at the bottom of the screen on to the target station.
What Does an Interchange Do?
An interchange improves the target station in two ways.
First and most obviously, the Interchange increases the station’s passenger capacity. If you’re playing Mini Metro in Normal or Extreme mode, then too much overcrowding for too long is how you lose the game. Eight or more passengers at a normal station normally starts the clock running, however if the station has been upgraded with an Interchange then overcrowding doesn’t kick in until there are 18 or more passengers waiting. That’s more than double capacity.
A more subtle improvement is that having an Interchange at a station significantly increases the speed at which passengers board and leave trains. This not only helps prevent the Interchange station filling up with passengers, it speeds the journeys of all trains stopping there. That has a knock-on effect as other stations then get trains more frequently, reducing their chances of over-crowding. A well-placed Interchange can have a positive effect across your whole network and really help in the later stages of the game.
How To Use An Interchange
From the above, we can see that there are two ways to use an Interchange. One is as an emergency game-saver when a station is badly over-crowding. There’s nothing wrong with that, and keeping an Interchange in reserve for such a situation is a valid strategy.
However to make best use of an Interchange, you really need to make use of its passenger speed boost. That means placing it where there is a lot of passenger traffic and preferably ensuring that several of your lines pass through it.
Remember that an interchange can not be removed or moved once placed, so think carefully about optimal positioning.