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What Even Is Population Density and Why Is Multi-City Transit So Hard

My ☕friend Ryan recently wrote up an explanation for how to calculate population density in a helpful manner—more helpful than the Wikipedia authors thought to do it.

Since I live near Edmonton, I figured I'd do the same process with Edmonton data, giving me a more familiar thing to compare it to.

Edmonton's is listed as 1,320.4/km². It doesn't surprise that Edmonton has over 100 m² more per person, considering it's large park system, but that's not stopping me from continuing down this rabbit hole.

Ditto:

Same same.

On top of that, it doesn't really make sense to care about what is in the city boundaries when the city butts up against another urban area still in the population centre for the sake of transit. Edmonton's population centre includes the City of St Albert in the northwest and the weird I-can't-recall-the-name-of-the-type-of-not-city of Sherwood park on the east. More on that later.

To a visiting person who doesn't really care, you could travel between the three entities by car and not really realise a difference. This is especially true for St Albert, where the largest buffer is the ring road corridor and a cemetery. There's bigger gaps between parts of Edmonton divided by the ring road.

(Why is this map not north-aligned? There's gotta be a reason.)

Edmonton's population centre density, including the areas not within Edmonton that StatsCan includes, is 1,836.2 people per km². So, still ~100 m² per person more in Edmonton.

At this point in Ryan's piece, he talks about how the population density numbers match up compared to Canadian cities with LRT transit. That's not completely relevant to Edmonton, since it already has a growing LRT network.

What is relevant to Edmonton, however, is the way the transit system is structured.

Thanks to the overarching structure of Metro Vancouver, their TransLink system connects a dozen cities that have their own governments (if I'm understanding it right). Looking at Vancouver's population centre map, it overlaps all these areas and there's actually a few outlying areas outside of the population centre (and other population centres) that are connected with the same transit network.

Meanwhile, in the Edmonton area, there's seven municipalities each running their own transit systems. All the ones outside of Edmonton have bus routes that go deep into the city, letting university students, for example, get to/from school without having to transfer. (Edmonton's only one going outside of the border to my knowledge is a special "Route 747" that connects to the airport and has a special fare.) Transferring from one system to another requires paying an additional fare, and back in the day of monthly bus passes, you'd need to buy multiple passes if you wanted to use multiple networks.

Comparing this to other networks, this is basically like bigger systems that have multiple zones to calculate how much to bill a rider… except it's different networks with different fares and budgets and vehicles.

In the last few years, the Edmonton-area transit systems got together to do a non-cash payment method that can cross borders. This is nice because in addition to the tap payment system for either your pre-paid "Arc card" or other form of plastic payment, it's just one system used everywhere.

The replacement of the monthly passes is now a cap on monthly spending: once you have spent a certain amount in a calendar month, additional rides paid for with that same card are free. This is great, but it's still separate networks and each has their own cap.

Why can't these different governments get together now and figure out a way to make it one system? I can understand that in the past, it would be hard to balance the books but it's the future now. We have all sorts of data of where people are going and how they're riding. It wouldn't be hard to compute a fare fair amount for how each city's equipment is being used and bill each municipality accordingly.

So population density turns out not to be a single number, and a "city" turns out not to be a single government. Edmonton’s urban fabric ignores those distinctions every day, whether someone is riding from Sherwood Park to campus or from St. Albert to downtown. Like how John Donne said, no man is an island, and furthermore, no city is an island. People cross the borders all the time. (This is also a local point of discussion recently with people talking about how the city's non-citizens benefit from taxpayer investment in rec. centres and the like.) The maps already know this. The riders already know this. The only thing still pretending otherwise is the paperwork.