All urban places have a grid of streets and when thinking about delivering change we need to think about how this functions as a network. With grid cities, most people think of America, perhaps New York with its series of streets- all straight and all connected at 90 degrees to each other. People wrongly assume that the medieval city with all its winding narrow streets is not a grid. Yet a grid simply requires the streets to connect to other streets or other public places.
In all grids, some streets are connected to more streets than others. Think of the high street in any town, or the market square- it will probably have the most other streets connected to it, and at one time it may well have been the main road between that town and the next town, or perhaps led to the only crossing point on the river.
The most connected street is probably the busiest street, therefore it is the place where shops and business activity appears. For businesses that require footfall, their managers generally apply common sense and choose to locate where most people pass by. Think of a cul-de-sac in a post war housing estate somewhere in suburbia. That street is only connected at one end, and it is probably only connected to a minor road at most. No one uses the cul-de-sac unless they have a reason to be there, so it is probably the quietest street, and probably the least appropriate street for a business that relies on passing trade. At the same time, it is also a place where the lack of people means crime is more likely to go unnoticed at the time it is committed. Yet the quiet of the cul-de-sac is a characteristic many seek.
So the structure of the street grid has a major impact on how we use a place, for it guides how we move across the urban space, how we access the buildings and uses within the place. If we want to make a street grid successful and walkable we need to follow a number of rules:
Most streets should be connected to other streets at each end.
Some streets should be more connected than others and these more connected streets should be wider and the focus of uses which require footfall and higher density development.
The length of street between any junction with another street should be no more than 80-100 metres, for that means it is easy for people to get from one place to another by walking.
The streets should be multi- use movement corridors, having safe and comfortable space for cars if necessary, cyclists and pedestrians.
There are other ways to use the structure of the streets to make the place more interesting and successful, but I will come onto that later. However, I should take this moment to explain what is not successful in street structures.
In the era after the second Great War there was a desire to separate vehicles and pedestrians, it was viewed that streets should be places for cars and people should be moved elsewhere. These ideas led to schemes where people were encouraged to move about the city via aerial walkways, underpasses, fenced from roads by railings or guided towards pedestrian only routes far away and out of sight from other road users, making them feel quiet but potentially unsafe.
A prime example of that design approach is the central walkway in the Barbican estate in London. People were expected to walk over the top and cars go beneath. But beneath is still the easiest way to walk from A to B so people still walk there and have to do so though what is a really unpleasant environment.
At this point please watch video 4 on street structures which will give you a bit more background and save me having to explain what the plan below the video shows. However, I urge you to study the plan in more detail after watching.
In order to design successful streets we must design them so that they are places for all road users. This means designing so that they are comfortable for pedestrians to use, accessible for cars if they must use them, but not designed to encourage or be dominated by car use. While many in the city wish to travel by car, regardless of how many urban expressways are built there can never be enough highway capacity to meet such demand. Fairly quickly a point is reached when roads are choked with cars such that the environment for pedestrians becomes abhorrent. Do you really want a road junction in a town centre like this one in Grimsby?
Successful cities are places where it is pleasant to walk around, and that means ensuring the streets are not dominated by traffic. It also means ensuring the streets are places where pedestrians and vehicles can move together safely and comfortably. This can be achieved through shared space schemes which usually involve stupendously expensive attempts to resurface the roads with cobbles of some variety and encouraging road users to mix. Alternatively, people think of traffic calming and all that does is annoy road users.
Simpler and cheaper ways exist to design streets that work for people and traffic. The simple approach of adding trees and making the vehicular carriageway narrower with some curvature will generally make people drive slower without realising, and that simultaneously makes the street a better place for people. Achieving this means that pedestrians feel more secure because there are enough other people on the street or in buildings facing onto the street so that a busy street or a well overlooked street is a safe street. We will cover that in a later section, but for now please shifty on over to section 8.
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