One of the most frequently heard terms recently has been the 15 minute city, as promulgated by the Mayor of Paris. Actually the term originates from the term ’20 minute neighbourhood’ coming from the 2018 Melbourne Plan.
Work undertaken in partnership with the Heart Foundation (Victoria) and across the Victorian Government identified the following hallmarks of a 20-minute neighbourhood. They must:
- be safe, accessible and well connected for pedestrians and cyclists to optimise active transport
- offer high-quality public realm and open spaces
- provide services and destinations that support local living
- facilitate access to quality public transport that connects people to jobs and higher-order services
- deliver housing/population at densities that make local services and transport viable
- facilitate thriving local economies.
Research shows that 20-minutes is the maximum time people are willing to walk to meet their daily needs locally.
Traditionally, the focal point for neighbourhoods were its high streets and local villages. While the structure of local shopping centres has changed over time, these places are an integral part of community life and fundamental to creating a city of 20-minute neighbourhoods.
‘Neighbourhood activity centres’ is the land-use planning term used to describe these local shopping centres. Community services and infrastructure are generally co-located with these places, planned and managed by local government. Neighbourhood activity centres provide retail services and goods (newsagent, bakery, supermarket), local entertainment facilities (cafes and restaurants) and local health services and facilities to meet daily needs.
The concept has become popular because high streets have shot down and people are forced to walk because of loss of public transport.
Of course sharp eyed planners will note this concept goes back a long way – for examples Dr Patrick’s Clarke (an Aecom colleague now) studies of Sustainable Residential Quality (Litchfields) for the GLA in 1997, and much further back to Clarence A. Perry’s concept of the Neighborhood Unit before and during the great depression which became so central to New Urbanisms concepts of Transit Orientated Development.
Can then the concept of the 15/20 min neighbourhood simply be collapsed to that of the neighbourhood unit?
Not entirely, for two reasons, firstly the neighbourhood unit was a child of its time and secondly the ‘walkable distance’ neighbourhood by itself does not have a fixed urban design concept of how it sites within a city and how it is laid out.
The neighbourhood unit was born in a time of rising car use and a reaction against traditional grid cities like New York where cars could access everywhere and there was a high accident rate. Neighbourhood units were islands of tranquility where through traffic ‘the town less highway’ was directed around the edge and in the centre walking networks would be largely car free. In the form of Radburn layouts
cars would access at the front and pedestrians at the back. We have learned since how this was an overreaction to the grid and how grids can be managed to discourage through traffic, such as with filtered permeability. In its original form there was little dedicated space for cyclists, however continental thinking from Denmark, Scandinavia and in particular the Netherlands show us the way. Dense segregated cycling grids no kore than 500m apart are shown to dramatically reduce car use. Two case studies stand out, the new town of Houten which has a ring road but no through roads for cars, only cycles built around a railway station.
And nearby Merwede, a district of inner city Uthrecht which is being developed so cars are communal with only three parking spaces per 10 houses.
We are beginning to tackle such concepts in UK urban design. For example LDA in the recent report for RTPI North envisaged largely car free local streets and neighbourhood ‘mobility centres’. There are difficult issues for urban design, can cars access every local street or do autonomous vehicles drop off and then park elsewhere, if so where? If we can solve this problem however we have the chance to recreate, without the famous problems of front and backs, the exquisite designs of the early radburn layouts and similar very narrow streets and alley housing blocks of early Garden cities, and at a range of densities.
Going back a generation further however we have Streetcar suburbs. Railway suburbs clustered around stations, but street car suburbs formed corridors, often biult out and perpendicular from the city grid form. In europe much more star like urban forms can be seen. . An underlying assumption in many TOD layouts is that they would be clustered around a BART type stations. Modern trams, BRT and Tram Trains travel faster and people don’t just jump on anywhere as you see from movie reels of the period. Optimal spacing of local services (as opposed to rapid metro services) is around 400m suggesting a string of pearls of 5 minute suburbs of neighbourhood centres and every 4 or 5th being a district centre where non stopping regional metro services (if you have them) stop.
Because the street cars have largely disappeared we often fail to recognise streetcar suburbs for what they are. To truly see the way they shaped urban form you have to find a sector of growth that did not rely on railways (as almost all English Cities did) and where trams persisted until late into the twentieth century, a good example is the North of Leeds (West Yorkshire is consulting on a vision for mass transit this week) in such cities such as Headingly, the West of Sheffield and West End Glasgow you invariably find the tram suburbs are by far the most desired neighbourhoods.
As cities grew beyond their street car suburbs however you increasingly had car traffic passing through them, and as trams travelled on central no segregated lanes congestion formed when they stopped. Trams were blamed for problems caused by cars and poor planning.
It still shocks me in an age now where we are planning an age of zero carbon sustainable suburbs how we fail to learn the lesson of streetcar suburbs, that of you want to succeed you don’t put transit (in whatever form) on segrated paths away from distributor roads carrying cars. Yet again and again we see this mistake, with distributor roads passing through the middle of suburbs and buses of infrequent services expected to share the same path. You often find these are edge of city areas where bypasses have been mooted since the 30s in some cases (e.g. Bedford) and urban extension plans come along, the TIA shows congestion, so a bypass disguised as a distributor is squeezed in and said to be essential to ‘unlock’ the site. LPAs use it as an excuse to squeeze S106 from developers and make bids to government infrastructure pots. You see examples such as Dorchester, Chippenham and Aylesbury – the latter strung through several schemes. It is bad unsustainable and fraudulent planning on many levels. It mixes up the concept of distributor, expressway and connector roads and makes efficient transit impossible, and creates pollution and traffic clogged neighbourhoods where buildings instead of forming high streets facing transit have buffers with neighbourhoods turning their backs in them. A terrible perverse incentive is government and Homes England pots like the Local Instructure fun which needs urgent review because of the sheer volume of carbon hogging schemes it is funding.
We really need to look back at Streetcar suburbs, and what made them tick, as inspiration for Zero Carbon Planning, and replan their focal points and grid connectivity for modern times. I actually have done this in a scheme of 35,000 or so homes for one large UK town that because of local politics is unlikely to publish its local plan at any time in the next 20 years.