Healthy Streets image

Health effects of air pollution

Healthy Streets Southwark

23 May 2023
7 min read

Changes to streets can improve public health.

Nikita Sinclair
Nikita Sinclair
Interim Director of Programme
Niamh McGarry
Dr. Niamh McGarry
Director of Impact, ClearView Research

It might seem obvious, but streets affect people’s health.  

Think about the street you live on. How it’s designed is likely to affect how active you can be. It’s the difference between being able to enjoy a walk to get some sun, or go for a run, or just get some fresh air.  

The design of our streets affects the air we breathe. How much polluting traffic a person is exposed to, for example, is determined by how a street is designed. And air pollution is the greatest environmental risk to health. It contributes to up to 4,000 deaths per year in London, 43,000 in the UK, and an estimated ten million per year globally.  

Then there’s the risk of traffic incidents. The design of our roads, cycle paths, and pavements affect how likely it is a person is hurt in a collision. There were a staggering 23,139 collisions in London alone in 2021. 

Streets with poor infrastructure and lots of vehicles travelling at high speeds contribute to poor air quality, noise pollution, light pollution, and greenhouse gas emissions. 

Are all streets created equally?

There’s social injustice hidden here: Poor street environments have an unequal effect on different groups. People living on low incomes, people from minoritised ethnicities, children, carers, older people, and people with illnesses or impaired mobility are all more likely to experience the worst effects of unhealthy street environments.  

There is also inequity in who has a say about local streets. Many people can’t get online and so can’t respond to council’s consultations (the same people often don’t have time to respond). These people are excluded from having a say in how streets can be made healthier and more welcoming.  

How did our project aim to improve health?

We partnered with Southwark Council, Healthy Streets, ClearView Research, and the MRC Epidemiology Unit at The University of Cambridge to test whether making changes to streets could make them healthier, more accessible places. 

Read our Healthy Streets report here

The project focused on three locations in the south London borough of Southwark, where families were more likely to be living on low incomes, have limited access to green spaces, and where there were high levels of childhood obesity, social housing, and air pollution.  

Several factors helped the project team decide on where to trial these street-level changes, including listening to residents’ concerns about various issues with their streets. 

This part of Marmont Road is a rat run for drivers…the junction with Goldsmiths Road is very dangerous for school children.

Resident's comment about Marmont Road in North Peckham project location

I can’t see how a wheelchair user can enter it currently as there are no dropped curb pavements on either side of the road here or nearby and the entrance to the garden is very tight off from a narrow pavement.

Resident's comment about Benhill Road in Brunswick Park project location

Traffic is fast and aggressive and takes little or no account of the fact that this is a densely inhabited residential area which is also home to convenience stores and a cafe. Those walking and cycling along Bagshot Street are subject to significant intimidation by this traffic.

Resident's comment about Bagshot Street in East Faraday project location

The Healthy Streets Approach informed the project, which meant adding traffic filters, wider footways, benches, and plants.

Smyrk Road before Healthy Streets trial
Smyrk Road before Healthy Streets trial
Smyrk Road after Healthy Streets trial
Smyrk Road after Healthy Streets trial


The project aimed to: 

  • Improve the Healthy Streets Check for Designers scores1 (or ‘HSCD’ score) for streets based in the project neighbourhoods 
  • reduce the number of motorised vehicles on the streets inside the project areas 
  • maintain or reduce vehicle speeds inside the project areas 
  • increase active travel  
  • increase the total time spent dwelling on the streets, including standing, sitting, playing and lying down 
  • to avoid displacing traffic and to have no negative effect on adjacent streets’ HSCD scores. 

Evaluating success and consulting with residents

Evaluating the success of the project focused on measuring three components, based on the Healthy Streets Evaluation Framework: 

  1. How the streets look and function, measured using the HSCD scoring system. 
  2. How people used the streets, which was measured by the number, types, and speeds of vehicles using the streets. Camera footage recorded levels of walking, cycling, and dwelling. 
  3. Residents’ opinions: For any project that aims to change streets, it’s vital to consult with local services and residents.  

Residents could give feedback via Southwark Council’s Commonplace website, and Southwark Council’s online consultation.  

In recognition that many people don’t use online consultations, the project team worked with ClearView Research to recruit and train nine people from the neighbourhoods as community researchers. Their role was to gather feedback from people living in their local area. 

Southwark Council also held fortnightly meetings with emergency services to make sure streets of strategic importance were not altered. 

Throughout the pandemic, the Government’s guidelines affected people’s behaviour. To be certain of whether changes to streets were influencing people’s behaviour, the project team used control streets, where they made no changes.  


Whereas active travel did not increase, the streets inside the project areas became healthier, safer, more accessible, and more pleasant to spend time on. This is demonstrated by increased HSCD scores inside all three neighbourhoods.  

Traffic volumes decreased in two neighbourhoods and the speed of traffic decreased across all three neighbourhoods. None of the adjacent streets saw a reduction in HSCD scores and most did not see an increase in traffic volumes. 

Graph demonstrating how the scores of streets involved in this trial improved, meaning they became healthier places to spend time.
Graph demonstrating how the scores of streets involved in this trial improved, meaning they became healthier places to spend time.

What did people think of the changes?

Just under 800 residents replied to Southwark Council’s consultation about whether to make the street changes permanent. Across all three neighbourhoods, most wanted to keep the street measures or build upon them. 

ClearView Research spoke to over 200 people across the neighbourhoods and found people’s views at the early stages of the project depended on their main mode of transport. Drivers were more likely to dislike the changes, while those who walked or cycled felt more positive. As time went on residents became more positive about the street changes, especially those living in the areas where the changes meant safer and less polluted streets. The community researchers also found that residents negative perceptions of the changes were based on concerns that traffic could be displaced to other nearby streets.

Dr Niamh McGarry, Director of Impact, ClearView Research:

“In the early stages of the project the community researchers found that most of the residents they spoke to didn’t know why the changes had happened or how long they would be in place for. This shows why it’s important for councils to communicate with residents: Not just to gather feedback about changes but to inform residents before changes are made and to communicate to residents about how and why streets are being changed.  

While some of that information could be found on the Council’s website, many residents don’t have the time or digital resources to access information online.  

Engaging communities early-on in these types of projects means councils and communities can work together to create effective change. This is why at, ClearView Research, we put co-creation at the heart of all our work, so that everything we do is informed and led by those who will be most affected.”

Over 600 people from across the neighbourhoods also gave feedback via Southwark Council’s Commonplace website.  

Seven to nine months after the project began, most people wanted the street-level changes to be made permanent. Many people felt the changes did not go far enough and wanted to see Southwark Council develop them to further improve neighbourhoods. 


For anyone working to make streets healthier, we have recommendations which focus on three themes: Expansion, engagement, and evaluation. 

Although the changes reduced the volume and speed of traffic, they did not improve levels of active travel. By expanding safe infrastructure to connect neighbourhoods, urban planners can encourage people to take longer journeys by active travel.  

Listening to the concerns of residents about streets – and understanding what changes residents would like – is vital to making urban areas healthier. This report recommends sustained engagement about the types of support that would help residents walk and cycle more often.  

Robust evaluation is key to understanding whether street level changes affect people’s health. It’s important to compare trial streets with control locations to measure the effectiveness of changes. Those control groups should be based on similar demographics and future projects evaluated for at least one year. 

Read our Healthy Streets report