Category Archives: Street Network Evolution

the evolution of urban street patterns over time

Who is the Problem

Current discussion on city growth paints a bleak picture of what has happened and, by inference, of what lies ahead.

But hope and despair are a matter of perspective and that’s where, I believe, much of the discussion lets us down; no historical or scientific perspective to give us a sense of what is disastrous growth, bad growth, good growth or excellent growth. That’s because most of city growth that has occurred in the last fifty to 60 years is readily termed SPRAWL (i.e. bad growth)

Instead, I believe, much writing sets up  idols of what might have been, usually irrelevant images from the past, and condemns the current situation as inadequate, poor, unsatisfactory and, consequently, disappointing.

A lot of opinions are expressed, coming from ideological camps, but no science to ground them. The science we expect is to tell us what the problem is and what is causing it. Instead, the science we get is a detailed description of symptoms, an array of images of the prefect answer and a full list of those who stop it form becoming a reality.

To put it succinctly what is happening to us is because of them.
As might be expected “them” is different people; it depends on who is writing, a matter of perspective. We are surrounded by villains, visionaries and victims all of whom have ingrained vices which inhibit or derail progress.
The list that follows shows the patterns of behaviour which have been attributed to the key participants in the development  game, developers, politicians, city staff,  planners, and consumers by a variety of writers coming from each of these categories:

 The Villains and their vices:

Developers (most disgraced):

  • Stick to uniform formulae
  • Avoid innovation (never be the first to try)
  • Eschew branching into multiple types of uses, housing types.
  • Prefer cheap land and unencumbered sites
  • Look at all land as reserve for development ( not preserve)
  • Engage in influence peddling particularly during elections
  • Pressure upper gvt levels to sway local decisions
  • Respond to piecemeal opportunities
  • Obey dictates that originate in distant headquarters
  • Seek to minimize risk and maximize profit
  • Let profit drive investment rather than city  plans
  • Dislike delays caused by NIMBY and avoid them by fitting in

Politicians at al levels (better but not much):

  • Loose their will when in office
  • Can be occasionally bought by big interests
  • Compete selfishly for development in their turf
  • Can rarely see past the 4-year term in office
  • Interfere or meddle capriciously with lower echelon decisions
  • See no problem with using up land that seems plentiful or low grade
  • See themselves as servants of the development industry
  • Allow development to occur contrary to policy or plan
  • Invest tax dollars foolishly for political gain
  • React to rather than direct growth proposals
  • Squeeze their constituents by letting housing prices and rents skyrocket
  • Let jobs and retail move out to the periphery 

Traffic engineers (most at fault)

  • Focus exclusively on traffic flow
  • Insist on past, proven roadway standards
  • Apply standards rigidly
  • Put safety above “good” street design
  • Solve safety concerns after multiple incidents 

Planners (often redeemed by good intentions)

  • Change their vision of the “good plan” every 20-30 years
  • Avoid setting “good” density thresholds
  • Do not know how to handle mixed use developments
  • Engage in paper planning without infrastructure or zoning supports
  • Plan transit service to a subdivision AFTER build-out. 

Consumers (often excused for not knowing what they are doing)

  • Young families like lots of house and yard space
  • Prefer single family homes, when they can afford them
  • Like the convenience and comfort of the car (job access also)
  • Are unwilling to live in fine-grained, mixed use developments
  • Resent and object densification when it comes closer to home
  • Are blind to ugliness of everyday landscapes through habit
  • See houses as an investment rung on a ladder (downsides unacceptable)
  • Prefer to be surrounded by their own ilk
  • Drive house size and price up by buying houses they can ill-afford

 The victims (and their predicament)

  • Cannot afford the housing they need for their families
  • Pay more for housing than normal
  • Are forced to drive because their jobs are not nearby

  The visionaries 

  • Care about the state of the environment
  • Worry about negative social outcomes (ie affordability and health)
  • Have plans and policies on visions for change
  • Change visions too frequently for long term planning to follow
  • Rarely, if ever, engage in development
  • Are generally not in elected public office
  • Have little or no influence on decisions by large corporations
  • Indulge frequently in “end-of-the-world” talk

 This web of attributions of fault, ill intent or ignorance helps little to understand the problem let alone solve it. People make choices in pursuit of personal gain, fulfilment, happiness, profit or the public good as they see it. Blaming these choices on tainted motives and assigning moral responsibility for the consequences will not change either the motives or the choices. 

Solutions lie not in finding out who is part of the problem but what the problem is.

The Portland Grid

Portland Porous ModelLegend has it that the two gentlemen who owned the prime piece of land, that was later to become the city of Portland, learned through reading and discussions that corner lots fetched a higher price than middle of the block ones. Consequently, they devised a plan that created the largest possible number of corner lots. As a result, Portland has the densest classic grid of all American cities that were founded around the middle of the 19th Century.

This story puts contemporary planning efforts and the discussion around them in a new light.
First it shows that what is admired today as a model of good urban planning had no other planning goals except the making of profit. The profit motive is currently often attributed to developers and portrayed as having a negative influence on planning and by contrast planning is said to be purely for the public good. This historic reference put an ironic twist to these perceptions.
Second, it shows that cities are at the mercy of diverse forces and conflicting perspectives that rarely can be expected to produce a consistent whole. They have and will continue to be assemblies of fragments, mosaics of many hands.
Third, that “profit” in its most general sense as “benefit” or “efficiency” should be embraced by planners as a true driver for planning new districts. The result from a future perspective could be as admirable as that of Portland’s.
To see how Portland’s grid might be shaped by a contemporary set off profit attributes, see the related article in this site.

Fusing Quality Atributes for Better Neighbourhoods

In each era of the history of the world’s cities, people lived in good neighbourhoods and in bad ones. The progression of affluence and invention has gradually given most of us decent houses, pleasant neighbourhoods and vibrant cities full of amenities and activities. Neighbourhood streets are clean and full of vegetation, houses on them are neat and comfortable-looking and neighbours are usually watchful, caring and like-minded.
So then, what is all the talk about the planning mistakes of the past 50 years? About building “bad” suburbs? About rediscovering the 19th century models? About “sprawl?”
Rather than repeating ugly words that blur our responses, we need to look at what bothers or inconveniences us in the neighbourhoods we live in and, conversely, what pleases—even delights—us. And then plan with quality in mind—suppress the bothersome and enhance the gratifying.
The most frequent complaint today is about traffic—traffic noise, dust, fumes and danger. Traffic is a nuisance and, at times, it can be injurious, even lethal. The higher the traffic volume the greater the nuisance until it reaches the point where a street becomes a virtual “traffic sewer”—mostly annoyance and no pleasure. We need to plan for less traffic in our neighbourhoods and a way to ensure that it will stay the same, for a while at least.
What do 19th century plans teach us about controlling traffic? Not surprisingly, not much. Until the invention of rail you could walk across most cities; there were too few people in them to constitute “traffic” and most were on foot—there was hardly a need to control noise, speed or volume. Still, those who could afford to lived “in (the) country” on estates away from the “buzz.”
The second inconvenience is that practically everything, including the kids’ playground, is too far to walk to. We have a great variety of things to choose from, but only by driving to them. When your car battery dies overnight, your horizon shrinks to your house. We need to plan for more activities within walking distance. The 19th century has a partial lesson for us; the comparatively short list of activities were all to be found on the main street, always at walking distance. And when rail helped cities grow, much could be found at the rail stops, still a convenient walk away. These are good hints for enhancing quality.
A third annoyance is being unable to find a friend’s house, even with good directions. In some neighbourhoods, streets take unexpected turns and twists and there is no set pattern you can “see” in your mind’s eye. A place only a block away can take many blocks of walking or driving to reach. Earlier cities had a regular pattern—the grid—that residents and visitors grasped immediately. More regularity and predictability in our neighbourhoods would remove this irritation.
We enjoy peace and tranquility when seeking to recover and recharge; nothing is more rejuvenating than deep sleep. Even when awake but in a contemplative mood we cherish tranquility. Whatever disrupts recovery or contemplation is an unwelcome intrusion. Let’s imbue our neighbourhood plans with tranquility.
We delight in nature—the freshness of nature, its changes and surprises and its vast repertoire of amazing living things—no imitation can replicate its direct experience. We would rejoice in daily contact with nature, if it were possible. Even a brief contact with it is enough to shed some of the stress caused by the city’s intensity. Early cities were surrounded by nature outside the perimeter walls and most citizens worked the land for a living. Experiencing nature was a daily event. Not so today; when most days are spent inside towers and houses. We are nature-starved. We need nature close by in our neighbourhoods and in our city centres.
We like mingling with friends and acquaintances in planned and casual occasions. These encounters happen on “common ground,” usually places of rest and relaxing settings. Squares, some streets and the “commons” (small parks) played that role in early cities. As well, pubs, cafes, church halls and social clubs offered similar places for mingling. Our streets are now taken over by asphalt and risk. Little mingling is left to chance. We need more casual common ground for chance encounters and mingling both in our neighbourhoods and our city centres.
Derived from pleasure and displeasure, here then are the elements of quality that we need to fuse in our neighbourhoods—tranquility, safety, proximity, nature and people places.
For tranquility and safety we must control the amount and speed of traffic; and no other planning tool achieves that more naturally and effectively than dead-end and crescent streets.
For proximity to amenities and conveniences we need to bring destinations closer to the neighbourhood—at the transit stop where lots of people go by and stores can be profitable.
Nature in the neighbourhood can serve a double function: as a people place and as a footpath connector. Strategically placed, a square can offer respite, linkage and an occasion for casual encounters.
And to find places easily, we can use clear geometry and embrace regularity and some repetition.
The picture on the left is a quadrant, the basic building block of the Fused Grid. The configuration shown here has been adapted to accommodate environmental features.
This fusion of elements of quality cannot be accomplished by each of the current planning methods alone: neither the traditional grid nor the contemporary irregular, unstructured suburban road pattern. A fusion of the two is needed.
A new prototype, a model, has been developed that brings all these elements together: the Fused Grid (See Figures 1 and 2). Introduced and promoted by Canada Mortgage and Housing Corporation (CMHC), it has already built some following among planners and builders.