A zoomable version of two overlayed transit maps from 1941 and 2011 lets you explore the similarities and differences after 70 years of change

A transit map is not just some means to help people to get around, it can tell you a lot about a city. Where do people live, where do they go, where’s lots of activity. It can be part of the local culture in a way, intimately familiar to so many people. Take two maps, from 70 years apart, overlay them and you can see even more stories emerging. This is what I did with this little mash-up that lets you zoom around a transit map of Montreal from 1941 and from 2011, sliding between the old and the new, and exploring the differences between then and now (a full screen version can be found here).

Many things have changed. Back then, the primary mode of transit was the tram. A system of hundreds of kilometres that has completely disappeared. Today we have the metro, and bus lines on the surface. 70 years ago the city used to be much smaller. Even the island itself was smaller – it grew as garbage got dumped along Pointe-Saint-Charles, and as land was won with the dirt dug up by the metro (or so the lore goes), expanding islands to build parks and expo 67. It seems that the city also used to be more bilingual, with more English street names, and the map itself bilingual.

One thing that I found surprising is how similar the network is today compared to 70 years ago. The tram may have gone, but many of their lines continue to this day, served by buses – despite the lack of tracks, the construction of the metro, and 70 years of change. It seems as if more lines have survived than buildings. Physical constructs made of brick and concrete have gone, whereas lines on a map remained, served by an ever changing fleet of vehicles running transient schedules.

Note how bus/tram-lines survived, whereas heavier rail didn’t. This is a bit surprising because it goes against an idea in transit development today, that rail lines induce more development because people perceive the infrastructure to be more permanent. But in a way it makes sense: if a rail line gets used less and less, it becomes economically impossible to operate. People will also demand the space to be used for something else, perhaps for cars (like the third track on the shoulder of the Victoria bridge), or to expand the city. A street-running transit line, not using any significant space, cheaper to operate and paid within a larger network, can survive as a less and less frequent bus.

Consider the 15 – the line used to be served by trams along the main transit corridor on St-Catherine street. Nowadays it is a bus running in parallel to two busy metro lines, on an awkward not-quite 30 minute schedule, split along two one-ways, routed around pedestrian areas. Today it serves mostly elderly people because the metro is not accessible enough: smack in downtown, it gets only about 8 riders per run*. It has nearly outlived it’s usefulness as a major transit line – a kind of Tomasson?

Other lines that have survived are the busiest in the network. While the busiest line today** (121 Sauvé) didn’t exist back then, many of the busiest routes of today already existed 70 years ago in some form or another (like the 39, 51, 65, 80). Maybe this means that the need to travel along certain directions is ingrained deep in the city structure, which may be stronger than the buildings themselves.

* ~530 people per weekday in 2011, ~64 runs a day, ~8.3 riders per run. ** The ridership numbers are from a dump of a few weeks of opus data from 2011.