What Mini Metro can teach us about real life public transport

My friend Andrew put me onto the game Mini Metro – it’s a rather addictive (at least to me) game where you design and run a metro (or tram) system. The game provides station locations, and travel demand patterns, and you have to work out how the lines should connect them.

Gradually more and more locations and people are added. The game finishes when the system gets overloaded and the stations get too crowded.

The game is available on numerous platforms – I play it on iPad, which seems very well suited to it.

The game is really more like buses than metros. Why? Because you can easily change the routes, and if nobody is waiting or needing to alight at a station, the vehicles don’t stop. And vehicles can overtake each other anywhere.

The more difficult “Extreme” mode is more restrictive – you can’t change routes. You can’t even move vehicles from one line to another.

The game has various scenarios based in different cities – including Melbourne.

Meanwhile in the real world

I was pondering what the game can teach us about real life public transport.

Frequency is good. In the game, passengers may have to change from line to line to reach their destination. If trains come through frequently, they’re not waiting for long, so crowds don’t grow too large.

Bunching is bad. In the real world it’s important to maintain even frequencies, and not let services bunch. This causes problems in the game too.

Diversity of destinations is good. The game creates different shapes, and may force you to have sections of line with the same shapes. This is analogous to lots of commuter stations which are a source of passengers, but rarely a destination. It means trains quickly become crowded in those sections.

A winning strategy in the game is to try and build your lines to have a mix of the station shapes – avoid the same shape multiple times in a row. This increases the chances of using your train capacity efficiently.

This is also true in real life – Melbourne’s CBD dominates train travel demand, but lines that serve intermediate destinations (for example Caulfield or Glenferrie which have university campuses, or Southland with its shopping centre) can mean some seats on the trains serve multiple passengers during one trip, making the system more efficient.

Passenger trips can be unpredictable. Sometimes the simulated passengers take unexpected routes to their destinations. So too in real life.

Lines with very busy and very quiet sections are difficult to manage. Capacity is wasted in the quiet section. You see this on Melbourne’s tram system – the CBD is very busy (in part due to the Free Tram Zone), but the suburban ends are relatively quiet (for the capacity provided), in part because many of them terminate in the middle of nowhere rather than making a logical connection to a railway station or other traffic generator.

Interchanges are useful, but challenging. If you can’t efficiently provide passengers with a one seat ride, then separate lines serving different destinations can help. But if something goes wrong, then queues of interchanging passengers can grow, overcrowding stations. If you want to see this in Melbourne, check the Federation Square tram stop in peak hour.

Station precincts develop over time. Part of the game has stations changing shape, such as from a common-or-garden circle to one of the rarer shapes. In real life, this happens – rail transport in particular often prompts development in the area immediately surrounding the station. It helps in the game because it adds diversity into a line – same in real life.

Larger vehicles can help. In the game you get the opportunity to add carriages, which can relieve crowding. This is analogous to replacing small trams or buses with larger (such as is happening around Melbourne’s tram network at present) or introducing longer trains (coming soon… eventually).

Crowding can develop very suddenly. Not to excuse government planning, but patronage growth can be unexpectedly fast, quickly overwhelming services. If the only fix is major infrastructure, this can take some time to resolve.

In Mini Metro, if stations get too crowded, the game ends. In real life, the government can get voted out.

The game is quite abstract, but good fun. Worth a look if you’re interested in such things.

• As I completed writing this post, I realised that transit planning expert Jarrett Walker has also written about Mini Metro