See new updates at the end, based on comments to May 4.

Ricky Leong in the Calgary Sun on why Calgary should spend more money serving far-flung suburbs:

Here’s the thing about providing transit to our far-flung suburban neighbourhoods. The benefits of new transit services will be felt by people everywhere in the city, not just those residents who choose to take the bus and train.

Fewer cars on the road should lead to better driving and cycling conditions for everyone, everywhere, for example.

Suburbanites choosing transit over private vehicles should also mean less wear and tear on roads, so the savings from reduced maintenance would be a net benefit to the entire city.

I’m not trying to embarrass Leung, because the error here is extremely common in journalism, as it is in public perceptions. Last November Lisa Margonelli built a long New York Times article around the same mistake.

Buses circulating in low density suburban areas (as opposed to express to Park-and-Rides) can serve many valid purposes, but getting cars off the road generally is not one of them.



The universal fact that these people are missing is that buses circulating in low-density areas — especially where street networks require transit to thread slow and complex labyrinths — is a predictably low-ridership service. Outside of a bit of rush-hour activity and sometimes a surge at school bell times, this is the fact of life about local service in low-density suburbs. If you don’t believe me, ask for your own transit agency’s stop-level ridership data and compare it to the density and walkability of the area around each stop. Apart from anomalies created by special land uses, you will find it is much higher in more urban parts of your community where these conditions are more favorable.

In 20 years of looking at detailed transit data, I’ve never seen a local suburban bus route whose performance (ridership per unit of service cost) was anywhere near that of a frequent urban bus route operating in area whose layout is favorable to transit.

(“Favorable to transit” means (a) higher density, (b) gridded local streets that provide easy direct access to stops for pedestrians, (c) a safe and pleasant pedestrian environment, (d) a mix of land uses and (e) simple linear paths, usually arterials, where transit can operate efficiently and effectively. These features tend to be found in older inner cities, but they can be replicated and in some cases even retrofitted.)

Indeed, because transit’s market is mostly the area within walking distance of a stop, low density and obstructed street patterns are the very definition of a poor transit market that will yield much lower ridership on investment, and that therefore justifies a poor level of service. Poor ridership out of low density isn’t an empirical fact; it comes close to being a mathematical fact, because in most cases density around a stop is the size of that stop’s market.

To claim that this predictably low-ridership service will result in “fewer cars on the road” is thus a geometrically incoherent claim. “Fewer cars on the road” is the result of people riding transit, not transit existing. So a service that is guaranteed to generate few riders per unit of cost will is guaranteed to get fewer cars off the road per unit of cost, compared to one that is guaranteed to generate many ridership per unit of cost — such as a line in transit-favorable geography or a rapid transit corridor.

The only high-ridership form of public transit that can serve low-density suburbs with obstructive street patterns is based on Park-and-Ride. Where land values permit, abundant park-and-ride and fast radial services can get cars off the road efficiently. Radial rapid transit (bus or rail) is also good because new transit-favorable neighborhoods can often be built later around its stations. Park-and-Ride needs to be understood broadly as also accommodating dropoffs, Bike-and-Ride, etc. But the key thing it does not require is for a bus to actually drive around inside a labyrinth of suburban local streets.

If a transit agency’s objective is to get cars off the road, then like any business you start by focusing on your competition’s weaknesses. The car is least convenient in areas of high density and good walkability, and geometrically these also provide the the highest ridership per unit of investment. The one other area is the suburban commute corridor — the freeway into the city — where congestion during peak periods makes the car a weak competitor. That’s why peak commute services — to Park-and-Ride, not to people’s front doors — is also a high-ridership prospect, and one that gets cars off the road efficiently.

Again, there’s nothing wrong with running bus routes around in low-density suburbs. But it is a low-ridership proposition and therefore can’t be justified by many sustainability outcomes; it’s justification has to lie in social needs and perceptions of equity among neighborhoods. If your city really wants to get cars off the road, however, it’s not a good way to serve that purpose.

This kind of confusion is why elected officials should be asked to think more clearly about how they want to balance the conflict between ridership-related goals (including lower subsidy, fewer cars on the road, and resulting sustainability outcomes) or coverage-related goals (including lifeline access and “equity” across all arts of a community. Both goals are noble, but don’t pretend to be doing one if you’re really doing the other.

Better still, ask elected boards to adopt policies about how much of the budget should be spent pursuing ridership — which means running services where high ridership is the predictable outcome — and how much should be spent pursuing coverage, i.e. distributing service everywhere regardless of low ridership. The Reno area’s transit board did this in 2005, as the result of work I did with them, and as a result, this whole conversation is much clearer, less personal, and more clearly tied to the community’s actual values.

For a more detailed exploration of this fundamental issue, see Chapter 10 of Human Transit.

UPDATES: Comments on this one are often critical, but what I see in them is that:

People have different definitions of “suburban” . It borders on being an unhelpful word but we don’t have a good word for it. What I meant was: landscapes whose geography is intrnsically hostile to transit, specifically the absence of all or most of the following: (a) relatively high density, (b) gridded local streets that provide easy direct access to stops for pedestrians, (c) a safe and pleasant pedestrian environment, (d) a mix of land uses and (e) simple linear paths, usually arterials, where transit can operate efficiently and effectively.

. It borders on being an unhelpful word but we don’t have a good word for it. What I meant was: landscapes whose geography is intrnsically hostile to transit, specifically the absence of all or most of the following: (a) relatively high density, (b) gridded local streets that provide easy direct access to stops for pedestrians, (c) a safe and pleasant pedestrian environment, (d) a mix of land uses and (e) simple linear paths, usually arterials, where transit can operate efficiently and effectively. As in almost everything, we’re talking about a spectrum rather than a pair of boxes. When I talk about dividing a budget between ridership and coverage, it does sound like I’m dividing the world into two boxes. In fact, many services are in the middle, contributing partly to a high-ridership outcome but with segments or periods that don’t. See Chapter 3 of Human Transit for more on this language problem …

rather than a pair of boxes. When I talk about dividing a budget between ridership and coverage, it does sound like I’m dividing the world into two boxes. In fact, many services are in the middle, contributing partly to a high-ridership outcome but with segments or periods that don’t. See Chapter 3 of Human Transit for more on this language problem … Ridership can be good by the standards of a local subarea and bad by citywide standards, if the entire subarea is less transit-friendly in the terms outlined above. Another way this issue is sometimes handled is to divide the region firmly into subarea, put budget walls between the services for each subarea, and then assess ridership by each subarea’s standards. This used to be how it worked in Seattle’s King County Metro, and the effect was that a line in the suburbs with a certain performance could be called successful while a line with the same performance closer-in to the city would be judged a failure. Not everyone could follow the “logic” of that and the agency has now let go of that rigidity.

if the entire subarea is less transit-friendly in the terms outlined above. Another way this issue is sometimes handled is to divide the region firmly into subarea, put budget walls between the services for each subarea, and then assess ridership by each subarea’s standards. This used to be how it worked in Seattle’s King County Metro, and the effect was that a line in the suburbs with a certain performance could be called successful while a line with the same performance closer-in to the city would be judged a failure. Not everyone could follow the “logic” of that and the agency has now let go of that rigidity. I am making a point about geometry, not about culture or values or psychology or ethics. I’m certainly not telling people where they should live, only about the consequences of those choices. But concealing or ignoring the facts of geometry leads to policy based on denial, and that leads us in circles rather than forward.

This isn’t an easy topic. Many of the terms are emotive. But there’s an important fact here. Again, see Chapters 9 and 10 of Human Transit for much more thorough discussion.