On “Transit-Oriented Development”, and the importance of being en route

President Barack Obama tours St Paul's new metro system in 2014, as transportation secretary Anthony Foxx looks on. Image: Getty.

One of the problems with discussions of Transit-Oriented Development – high density development around transport hubs, known as TOD – is that the term sounds much too specialised. 

We hear talk of TODs as a special class of developments, which brings special requirements and possibilities, and perhaps requiring special expertise. In North America, we often hear that a certain development is or isn’t aTOD, as though transit-orientation were not (as it obviously is) a matter of degree.

Moreover, most of the urban development decisions that will determine the future viability of transit are not decisions about TODs. Most of them are not even conscious decisions about transit. The literature of “how to build TODs” is useless in these situations. What people need are simple guidelines about transit that they can keep in the back of their minds, and on their checklists, as they plan ALL kinds of urban development. The same principles could help institutions and individuals decide where to locate.


As a transit planner, I constantly encounter situations where something has been built in a way that precludes quality transit – where I can see that, if it had been built a little differently, transit would have been possible without compromising any of the development’s other goals.

I’ve also dealt with situations where a transit-dependent institution – say, a social-service office catering to low-income people, or an assisted living centre for active seniors – chose to locate in a place where the land was cheap because the transport options were terrible – and then blamed the transit agency for not running buses to their inaccessible site.

These cases are the result of a poor respect and understanding of transit as a background consideration in all urban development. Ultimately, they matter at least as much as the official TODs schemes do in determining the potential for transit in the cities of tomorrow.

If I could put one sentence about transit in the mind of every developer, every land use planner, indeed anyone who makes a decision about where to locate anything, the sentence would be this: Be on the Way. If you want to be sure you’ll have good transit, be on the way from one transit destination to another.

 

An efficient transit line – and hence one that will support good service – connects multiple points; but it’s also reasonably straight, so that it’s perceived as a direct route between any two points on the line. For that reason, good transit geography is any geography in which good transit destinations are on a direct path between other good transit destinations. (Obviously, this is not always a geometrically straight line; it may be a path defined by existing roads or rail corridors that everyone perceives as reasonably direct given the terrain.)

A bad geography is one that indulges in cul-de-sacs on any scale. It sets destinations a little back from the line, so that transit must either bypass them or deviate to them, where deviating means delaying all the other passengers riding through this point.

The same problem arises at many scales:

  • A person who lives at the end of a long cul-de-sac road complains that the bus doesn’t go by her house.
  • A small shopping centre or grocery store sets itself too far back from its street, even though the street is where the transit service is.
  • A university, hospital, business park or other campus-style development positions itself on a hill, often at the end of a road leading only to it, or on a road at the edge of the city where there is nothing further beyond it. This makes the institution look and feel important, but limits the possibilities for transit service because it can only be served by lines that end there.
  • An entire suburb, perhaps one called a Transit-Oriented Development, is located in such a way that no regionally logical transit line will ever get to its town centre, except for routes that go only there.

One of the major failings of Peter Calthorpe’s early 1990s project Laguna West, in Sacramento, is that the town centre is located in a place where no regionally logical transit line could ever serve it. Laguna West still has mediocre transit service because it’s impossible to combine its market with any other markets – which is what you have to do to create an efficient transit line.

Land use planners urgently need simple tools to catch these problems. Until those tools are developed and built into training, they’d do well to just remember one sentence: Be on the Way.

Jarrett Walker is an international consultant in public transit network design and policy, based in Portland, Oregon. He is also the author of  “Human Transit: How clearer thinking about public transit can enrich our communities and our lives".

This article was originally written for his blog, and is reposted here with permission. All images courtesy of the author.

 
 
 
 

Tackling toxic air in our cities is also a matter of social justice

Oh, lovely. Image: Getty.

Clean Air Zones are often dismissed by critics as socially unfair. The thinking goes that charging older and more polluting private cars will disproportionately impact lower income households who cannot afford expensive cleaner alternatives such as electric vehicles.

But this argument doesn’t consider who is most affected by polluted air. When comparing the latest deprivation data to nitrogen dioxide background concentration data, the relationship is clear: the most polluted areas are also disproportionately poorer.

In UK cities, 16 per cent of people living in the most polluted areas also live in one of the top 10 per cent most deprived neighbourhoods, against 2 per cent who live in the least deprived areas.

The graph below shows the average background concentration of NO2 compared against neighbourhoods ranked by deprivation. For all English cities in aggregate, pollution levels rise as neighbourhoods become more deprived (although interestingly this pattern doesn’t hold for more rural areas).

Average NO2 concentration and deprivation levels. Source: IMD, MHCLG (2019); background mapping for local authorities, Defra (2019).

The graph also shows the cities in which the gap in pollution concentration between the most and the least deprived areas is the highest, which includes some of the UK’s largest urban areas.  In Sheffield, Leeds and Birmingham, there is a respective 46, 42 and 33 per cent difference in NO2 concentration between the poorest and the wealthiest areas – almost double the national urban average gap, at around 26 per cent.

One possible explanation for these inequalities in exposure to toxic air is that low-income people are more likely to live near busy roads. Our data on roadside pollution suggests that, in London, 50 per cent of roads located in the most deprived areas are above legal limits, against 4 per cent in the least deprived. In a number of large cities (Birmingham, Manchester, Sheffield), none of the roads located in the least deprived areas are estimated to be breaching legal limits.

This has a knock-on impact on health. Poor quality air is known to cause health issues such as cardiovascular disease, lung cancer and asthma. Given the particularly poor quality of air in deprived areas, this is likely to contribute to the gap in health and life expectancy inequalities as well as economic ones between neighbourhoods.


The financial impact of policies such as clean air zones on poorer people is a valid concern. But it is not a justifiable reason for inaction. Mitigating policies such as scrappage schemes, which have been put in place in London, can deal with the former concern while still targeting an issue that disproportionately affects the poor.

As the Centre for Cities’ Cities Outlook report showed, people are dying across the country as a result of the air that they breathe. Clean air zones are one of a number of policies that cities can use to help reduce this, with benefits for their poorer residents in particular.

Valentine Quinio is a researcher at the Centre for Cities, on whose blog this post first appeared.