Low traffic neighbourhoods reduce pollution and traffic in surrounding areas, study finds

A Low Traffic Neighbourhood in Dulwich, south London  (In Pictures via Getty Images)
A Low Traffic Neighbourhood in Dulwich, south London (In Pictures via Getty Images)

Low traffic neighbourhoods (LTNs) reduce traffic and air pollution and don’t displace the problems elsewhere, according to new research.

The study by researchers at Imperial College London examined three LTNs in Islington compared pollution and traffic levels inside the zones, on surrounding streets and at control sites further away.

The LTNs – in St Peter’s, Canonbury and Clerkenwell – were all put in place during July and September 2020.

The study built a model which controlled for the other factors which affect traffic or pollution, such as the Covid rules in place, school holidays or weather.

It found that concentrations of nitrogen dioxide fell by 5.7 percent within the LTNs and by just under nine percent on their boundaries, compared to the control sites.

They also found that traffic dropped by over half inside the LTNs and by 13 percent at the boundaries, compared to the control sites.

Dr Audrey de Nazelle, from Imperial’s Centre for Environmental Policy, said: “This research effectively disproves the argument that low-traffic zones will necessarily cause an increase in traffic and air pollution in neighbouring streets.

An anti-LTN protest in Ealing (Handout)
An anti-LTN protest in Ealing (Handout)

“In the three areas we looked at, they reduced both traffic volumes and, significantly, air pollution both inside and on the edges of the zone.

“Alongside the other benefits of LTNs that have been shown in previous research – such as improvements in safety and an increase in walking and cycling – this makes a very strong argument in their favour.”

Co-author PhD student Helen Yang said the model was the first to analyse the effects of LTNs on surrounding areas, saying the results were “really encouraging”.

However, she added: “We worked with a relatively small data set and further research is now needed to confirm these findings at a larger scale.”

More than 100 LTNs, which are designed to prevent drivers using residential streets as short cuts, and 500 school streets, which ban non-residents from driving past schools at the start and end of the school day, are in place across the capital.

However, critics have staged protests against them, with some saying they are too disruptive and often introduced without thorough consultations from local councils.