Global trends in transit maps
Particular regions of the Earth have different ways of expressing the information people use to plan their daily commute. These varying types of transit map all attempt to communicate this information as quickly and easily as possible, utilising different strategies to do so.
Schematic vs. Geographic
The most obvious difference between transit maps around the world is whether they utilise a schematic diagram or a geographic map to construct their transit map. A geographic map is defined as a map where the route is overlaid on top of the natural or manmade geography behind it. For example, a geographic bus map will have bus routes that are overlaid onto the road system. Geographic maps will also often have geographical features that are accurately represented. In the majority of geographic maps, any natural borders such as coastlines will not be simplified to a series of lines. The geographic map is the traditional way of drawing a map, and the majority of maps before 2000 are geographic. Your everyday road map (if those even exist anymore) would be classified as a geographic map. Bus maps and ferry maps are historically more often depicted using geographic maps.
A schematic map is defined as a map where the route is simplified to a series of connected line intervals, where there is a consistent grid structure and only a certain series of angles can be used in the route. For example, a schematic map may only have 90-degree or 135-degree turns. In recent years, more quirky angle combinations have been used in transit maps, such as only 18-degree multiples being allowed, or an isometric grid, where lines are always 30 degrees above or below the horizontal. Even maps based on circular arrangements would be classified as schematic. Ever since Harry Beck created his iconic London Tube map in 1931, people have been using schematic diagrams to represent their transit systems. Rail and metro maps are historically more frequently depicted using schematic maps, which many people refer to as “diagrams” rather than maps.
As the map below shows, the majority of the globe uses schematic diagrams to represent their transit systems — the one exception being the Americas, which have a mix of both. I have gathered four of the largest cities from each continent (except Antarctica) and determined whether they use a schematic or geographic map, the information from which is shown below.
Europe’s map designs are usually cleaner, as geographic maps generally provide too much information to the user to the point that it becomes unreadable. However, there can be good and bad examples of both schematic and geographic maps.
And while it is usually a good idea to not have schematic and geographic elements in the same map, sometimes this can be effective, as long as it is clearly indicated.
Integration of service maps
While most transit maps are unimodal, only depicting one mode of transportation such as train, bus, etc., others depict the vast network of buses and trains of an entire city. It is important that a map does not fall into two extremes. The first extreme is a transit map that does not display any service connections. For example, a train map should indicate important interchanges to bus, ferry and tram routes, if applicable, as well as indicating where the central business areas are. After all, these maps don’t exist in a mode vacuum, and it is important that its functionality is not compromised. The other extreme is a map that attempts to cram in all of the transit information of an entire city, which is often unsuccessful as the user simply does not know where to look, and which often compromises the design of the map.
