The metro system in the vanilla game is somewhat lackluster, so I highly recommend the Metro Overhaul Mod (MOM) and wide availability of custom stations on the Workshop.

This guide is intended to explain the general game mechanics and design process of metro networks, regardless of player experience. If you want something more relevant to optimization and realism, look elsewhere.

Cims are simple beings, at least in terms of commuting:
Note that "workplace" includes industrial and office zones, schools and service buildings (e.g. hospitals, bus depots). Leisure activities should also be considered.

Lines should connect residential areas to workplaces, parks and unique buildings; if there isn't a direct route, ensure transfers are available. In lower density regions, stations should be farther apart and connect to local bus services, where they can become feeder systems. Consider interchange points with regional rail as well; they can provide faster, higher capacity alternate routes.

Most real-world metro network evolution is surprisingly similar, and can therefore be categorized by their connection patterns.

• directly connects high volume nodes
  
• combined lines provide high capacity
  
• limited service area

• large service area
  
• requires large hub stations
  
• limited connections between branches

• provides alternate routes
  
• moderate service area
  
• complex and expensive

Note that these aren't strict divisions; most networks are hybrids of these categories, and some just do their own thing.

To demonstrate the design process, I'll use one of the cities I've planned on the Islands map.


Five lines will radiate outward from the the higher density city center to industrial areas and suburbs. Transfer stations are frequent, and transit hubs will be built at popular destinations like airports, train stations and harbors.


All three network topologies are visible - the central grid acts as a hub, with branching trunk lines as spokes.

If you're playing vanilla, connections where lines cross at right angles can be a hassle, so I've used custom Workshop stations. More transfer points generally correlates with faster trips, but they aren't necessary for outlying regions; buses are a better option where the extra capacity isn't required.

Try sketching out a network in Google Drawings (which I used) or some other vector graphics software - it can help visualize connections and potential problems before spending those hard-earned tax dollars.

Once settled on a design, why not create an accompanying schematic? I've used MetroMapMaker[metromapmaker.com] to generate this diagram. Feel free to link yours in a comment, it might help others plan their networks.