A long-lasting concern in communicating transit to the public is how to best package the information: whether to do something like the iconic London Underground map with its complete ignoring of geographical reality or just slap the transit stations on a geographical map and let that do the work, or something in between.
Even London has gone through some evolution historically on this.
And perhaps obviously many cities do both, or a middle ground, or a mixture, since there are obvious benefits to each: the clarity of how the lines intersect and work on the one hand, and the ability to use the transit to get to the actual city on the other.
Montréal, which I recently visited, is I think a really good object lesson in these benefits (and corresponding disadvantages) because its two systems rely heavily on the opposite kinds of information. So today I want to use the REM and the Montréal Metro to illustrate some of the affordances of each--that is, what each kind of map allows to happen and what it makes harder.
1. Diagrams and Intersections
Back in the day, before I was anything of who I am today really, I spent two summers at Canada/USA Mathcamp, a camp for those who wished to pursue more knowledge in math than their middle schools and high schools would provide (I can say definitively that I was the least mathematically gifted student at those camps, but that's neither here nor there--I went). And while I was there, I spent a lot of time, as any normal eighth-grade student would, thinking about graph theory. I remember very little about it now, but the reason for this little trip down memory lane is that the use of graph theory frequently relies on simplifying complex systems into patterns of lines and intersections. Think of the iconic Bridges of Königsberg problem: the question is about how or whether you can pass over bridges in particular manner, but the solution relies on ignoring the physicality of the bridges and their locations in space and treating them as lines between points on a map. An Euler Tour (thanks Leonhard!) doesn't care about what sights might be on the islands that the bridges lead to; it cares only about the graph produced and its connections.
While tourists and commuters aren't solving graph theory problems, they do often care a lot more about what the station connections are than where they are in the city, so there is a major advantage to a diagram rather than a geographical map, especially if the geography will be distracting. I don't care if I'm going underneath Mont-Royal on a segment of the REM if I can't get off the train anyway!
This REM map, therefore, is highly useful if my concern is "where can I take the REM to, how many stops will there be before I get off, and where should I transfer if I need to go somewhere else." You might recognize these as extremely common concerns for someone taking transit! If I'm not planning on walking/biking myself between stops or between lines, which most users are not, I don't care so much where they fall on the map, as long as I can identify which stop I want for my destination. Once that's identified (possibly on a geographical map), all I need do is follow the diagram of the system to figure out how to use that system to get to my destination.
The geography of it all matters very little. The exceptions would be places like Leicester Square/Covent Garden in London, where the walk is short enough that I could genuinely use both stops for the same destination. But for systems with more reasonable stop spacing, like the REM, the diagram is not only sufficient, it's better.
2. Orientation in Space
But the converse is also true: there are times it's really nice to know where you actually are--especially if you're interacting with other systems, like a bus system, or a non-grid street pattern, or a bike network.
And for this, the system on the Montréal Metro shines.
Every Metro station has one of these: it needs updating with the REM, but it's a consistent reminder of where the Metro actually goes in the physical city of Montréal (and its neighbors, no shade to Laval or anything). That means that if I'm interested in a neighborhood, or anything else that's larger than a single point on a map, I'll have a much easier time finding my way there than through a purely diagrammatic approach.
This kind of map detail makes it really easy to tell where a specific location you might be going to is in relation to the Metro stations, and I really appreciated it when my phone got low on battery.
There are some factors that help here: Montréal has a fairly straightforward geography for a map like this (unlike say the sprawl of London or Paris or the island-centric nature of the NYC subway) and the lines don't tend to go in completely irrational ways, which means that a geographical map is closer to a diagram here than it would be in a city where the lines curve a lot more and there are more distracting features on the regular map. Since Montréal's Metro is mostly only on one landmass with fairly straight lines (or at least smoothish curves) it doesn't introduce much confusion to use a geographical map, and it provides some grounding in the actual geography of the city for those who benefit from it.
You can even inset one into the other, as they do, allowing a diagram and a geographical map to speak to each other in concert, and getting some of the benefits of both at once.
3. Hybridity
And of course, as astute readers will probably have guessed or noted, there's nothing that requires full commitment to either bit.
This kind of map, featured at most Metro stations (I think all, actually), is a minor hybrid. It is diagrammatic, but it includes certain indicative features of the island (like the river) and therefore orients the reader to the geography without pressing on it. London does something similar, in fact, despite being the iconic diagrammatic map, because a (diagrammatic, simplified) version of the Thames is visible on the Underground map. Montréal has gone a little more geographically precise, but not much, and it helps.
It also includes these lovely travel times, which I really liked!
The REM also has a hybrid map, one that again helps clarify where you are without pressing all the street-by-street detail of that Metro map onto you.
And of course they have much more geographically precise maps in the stations about that particular station, because once you're there the diagram doesn't help much at all.
Hopefully this helps in terms of identifying the benefits of both of these approaches. I haven't emphasized the negatives, but presumably they are visible by implication: a geographical map can get too busy or complex by including all the other detail of a city, and doesn't help if all you want to know is how far you are by train; a diagrammatic map only gets you to the point of the station and unless you're like me and just traveling to say you saw a station, that's not actually the goal of transit.
Even though there are some pretty cool-looking stations to visit!
But since both systems have their benefits, its probably unsurprising that some kind of hybrid is the ideal middle ground--even if the systems may have slightly different views of where that ideal middle is.



















































