On 15 minute neighbourhoods

15 (or 20) minute neighbourhoods are an immensely good idea. The goal is to reduce the need for use of cars by ensuring that routine daily activities are in range of walking, cycling or possibly public transport. This encourages active travel, with associated health benefits, as well as reducing GHG emissions. There is no single accepted definition of what this actually means in terms of distance (how far do you walk in 15 minutes?) or what services are supposed to be in this range (school, doctor, shops …). Here I report on some findings from a survey of residents in Oxfordshire [1] about what facilities people want, a related report [2] and a literature review of the subject [3]. Also there are some numbers on how well Cambridge scores from the Cambridge City Portrait: State of the City report [4].

Some transport statistics – more shopping trips than commuting.

First, a little reminder about our travel habits. You may not be typical. The latest data from Transport Statistics Great Britain is from 2021 [5] which is still affected by Covid so I compare it with 2018.

• Commuting accounts for only 13% of trips (down from 15% in 2018) and only 19% of distance travelled, down from 20% in 2018
• 76% by car, up from 68% in 2018
• Shopping accounts for 18% of trips and 11% of distance
• 84% by car, the same as in 2018
• Going to and from school accounts for 13% of trips and 11% of distance
• 59% by car (up from 56% in 2018)

Our use of buses massively reduced due to Covid – 21% in 2018 down to 4% in 2021. Recent measures such as the low fixed fares should reverse the trend somewhat.

What facilities would we like to have nearby? Green space comes top.

The facilities generally considered important are for food shopping (supermarkets and local shops), schools, health (GP and pharmacy), green space, sports facilities, pubs and cafes, community centres and sometimes employment. It is nice to be able to walk or cycle to work, but as we have seen the majority of people drive. The Oxfordshire study asked their residents what was most important for them. The survey included a good mix of people living in towns, suburbs and rural areas but was rather overweight in older people – 37% of 65 or over compared to 20% in the population. Also, there was a dearth of families – three quarters had no children in the household. Otherwise I think we can consider them reasonably representative of the area. They were asked to select their top six priority facilities out of a set of nineteen.

The amenities most often selected were:

• Park or other green space 
• Shop selling basics including newspapers
• Post Office
• GP surgery/health centre
• Pharmacy
• Supermarket

The top ranking for 'Parks and other green space' is confirmed in other studies. For example, a survey commissioned by Cambridge City Council in Feb-Mar this year [10] asked ‘Thinking about where you live what are the things that make your daily life safe, happy and healthy? Green spaces came top, followed by 'Community, family and friends' then ‘Proximity to shops, amenities, work, family and friends, able to walk and cycle’.

I was very surprised by the Post Office ranking so high as most PO services can be done online and you can get your postman to pick up parcels. The Post Office was highest priority for people living in villages but, even among people living in Oxford and suburbs this came third. I was also surprised that schools did not feature more highly: Nursery/Primary school came only 10th. However this is probably due to having so few families in the survey.

There are no social centres in the top six but they were not far behind. Coffee shops came 7th, pubs 8th and day centres 11th. The respondents were very mixed in their desire for these facilities. 43% listed neither coffee shop nor pub while 14% wanted both. 

The survey also asked if these facilities were available close by. Less than half (46%) had a convenient GP or health centre. However 81% said they did have green space in range. I don’t think that would be the case in all parts of the country.

The most missed facilities (wanted but not in walking range) were a farmers market and a bike shop.

How far are we prepared to walk? 15 minutes.

The survey asked how long people were prepared to walk each way to get to their amenities. 75% would go for 15 minutes, only 40% would go for 20 minutes. 15 minutes could be a mile for a fit person but less for many people. The usual assumption is 20 minutes per mile so 15 minutes means ¾ of a mile or 1.2 km.

Younger people were in more of a hurry. No-one under 34 found more than 20 minutes acceptable. This is doubtless because they are more pressed for time. Maybe they can walk faster or cycle instead.

Distance is not the only criterion – quality is also important.

15 minutes walk along a quiet tree-lined avenue is one thing but 15 minutes along a busy road is another. The best walking routes are low in traffic noise, ideally with trees, but above all safe – from traffic, from crime and accidents. Uneven pavements need to be fixed and parking on pavements should be strongly discouraged [2]. Public transport needs to be safe too, and access to it involves walking on the street so the same issues apply.

Similarly, the amenities provided need to be useful. Green space full of litter is not very nice, though volunteer work could help to fix this. Shops that are convenient but too expensive for the local people will not get much trade.

Population density needed - quite doable with mixed housing

The literature review references a book [7] with some illustrative figures for how many people you need to support various facilities. You need 1,500 for a local shop, 4,000 for a primary school but 10,000 for a typical health centre with 4 GPs. When I was young our doctor worked on their own (plus a receptionist) but that is unusual these days. There are advantages to having a group practice such as sharing out-of-hours service and potential for specialisation as well as help with all the paperwork. 

To get 10,000 people within a 10 minute walk (the book considers 20 minute neighbourhoods, meaning 10 minutes each way) you need 50-90 people/hectare depending on how direct the walking routes are [7]. The typical household size is now 2.4 so, that means 20-40 dwellings per hectare (dph). That includes gardens and roads but you also need some space for the amenities as well, so say 25-45 dph. This is eminently doable. According to The Designing Buildings Wiki 20 dph is typical for a suburban area [6]. However it is possible to achieve higher densities – up to 50 dph with a mix of semi detached and short terraces [8].

Cambridge on average achieves the 15 minute criteria if you allow cycling – but not for everyone.

Cambridge overall has a population density of 36 people/hectare [9] which is too low for 20 minute neighbourhoods (10 minutes each way) but just about OK for 15 minutes each way. 

The Cambridge City Portrait: State of the City [4] includes an assessment of travel times for essential services including work as well as GPs, food and retail etc. It reports the mean minimum journey time is 14.4 minutes – comfortably inside the 15 minute limit. However these timings allow cycling as well as walking and public transport. Also, although the average time was inside the limit, this does not apply to everyone. For people living in Kings Hedges, Arbury, East Chesterton and East Barnwell/Abbey, journey times were longer (see chart). These are also the most deprived areas. 

Journey times versus deprivation index for wards in Cambridge, from [4]. Includes PT (Public Transport), walking and cycling.

Planning for 15-minute neighbourhoods.

There is not a huge amount that the local authority planning departments can do to promote 15 minute access to amenities. They have very limited powers to require retail and other amenities to be provided in new developments. Even when premises are provided, they can often be converted to housing later under permitted development rules [2]. Since demand for housing is very high this is very attractive for developers.

This is unfortunate. It would make sense for councils to be able to allocate land for service provision, even if they cannot force organisations to use it. They should also be able to veto change of land use where this would be detrimental to the 15 minute target. 

[1] 15 Minute Neighbourhood Survey Results (Brenda Boardman and Alison Hill, Coalition for Healthy Streets and Active Travel) March 2022

[2] Why we need 5 Minute Neighbourhoods (Alison Hill and Brenda Boardman, Coalition for Healthy Streets and Active Travel) March 2022

[3] Unpacking the concept of 20-minute neighbourhoods: disentangling “desired outcomes” from the “means” available for achieving them (Husam AlWaer and Ian Cooper) Feb 2023)

[4] Cambridge City Portrait Appendix D State of the City 2023 (Cambridge Econometrics for Cambridge City Council (June 2023)

[5] Transport Statistics Great Britain table NTS0409

[6] Designing Buildings Wiki: Housing density

[7] Barton, H. (2016), City of Well-Being: A Radical Guide to Planning, Routledge: Taylor & Francis, Thames. 

[8] Planning: Suburban housing density (Richard MacCormac, Architects Journal) 2011

[9] Population density, persons per hectare in Cambridge (LG Inform) 

[10] Putting Residents and Communities at the Heart of the Conversation (Cambridge City Council) 2023