London's Ultra Low Emission Zone and active travel to school: a qualitative study exploring the experiences of children, families and teachers.
BMJ Open 2025 ; 15: e091929.
Alliott O, van Sluijs E, Dove R, Kalsi H, Mitchell J, Mudway I, Randhawa G, Sartori L, Scales J, Wood HE, Griffiths C, Guell C, Panter J
DOI : 10.1136/bmjopen-2024-091929
PubMed ID : 40032382
PMCID :
URL : https://bmjopen.bmj.com/content/15/3/e091929
Abstract
Taking a qualitative approach, we aimed to understand how London's Ultra Low Emission Zone (ULEZ) might work to change behaviour and improve health in the context of the school journey.
Primary qualitative study embedded within an existing natural experimental study.
A population-level health intervention implemented across London.
Purposive sampling was used to recruit children (aged 10-11 years) from ethnically and socioeconomically diverse backgrounds within an existing cohort study, Children's Health in London and Luton.
In-person and online interviews were conducted with 21 families and seven teachers from the children's schools between November 2022 and March 2023. Verbatim transcripts were analysed drawing on Braun and Clarke's reflexive thematic analysis and guided by realist evaluation principles to identify contexts, mechanisms and outcomes using NVivo.
Common context, mechanism, outcome (CMO) configurations were identified reflecting congruent narratives across children, parents and teachers, for example, current active travellers (context) reported reductions in pollution (mechanism) leading to improvements in health, including alleviated symptoms of asthma (outcome). These CMOs were broadly captured by two themes: (i) how you travelled before the ULEZ matters: the impact of travel mode on experiences of the ULEZ and (ii) your context matters: the role of socioeconomic position in experiences of the ULEZ. Participants highlighted the potential for the ULEZ to positively impact their choice of travel mode to school, experiences of the journey and their health. However, the impact of the ULEZ differed inequitably by journey length, travel mode before implementation and access to reliable and affordable public transport.
The capacity for the ULEZ to both narrow and exacerbate inequities across different travel contexts suggests when developing such schemes, more emphasis needs to be placed on providing accessible and affordable alternatives to driving.
Lay Summary
How London’s Ultra Low Emission Zone Affects School Journeys and Health
This study examined how London’s Ultra Low Emission Zone (ULEZ) affects families’ travel choices and health, focusing on school journeys. Researchers interviewed children, parents and teachers from diverse backgrounds to understand their experiences of the ULEZ. The findings shed light on how this intervention has influenced travel behaviour, air quality, and health, revealing both opportunities and challenges in achieving its intended goals.
The London ULEZ, introduced in 2019, charges drivers of high-polluting vehicles a fee to enter designated zones. This policy aims to reduce air pollution, encourage active travel modes like walking or cycling and improve public health. We found that the impact of the ULEZ varied based on families’ circumstances.
Families living more centrally who already used active modes of travel reported noticeable benefits. Cleaner air and reduced traffic enhanced their overall journey experiences, encouraged outdoor activities and alleviated conditions like asthma. For example, some parents described taking longer walks home though parks, while children reported begin able to breathe more easily during their commute.
However, those who relied on cars, especially from lower-income suburban areas, faced challenges like increased financial strain due to daily charges or the high cost of upgrading to compliant vehicles. These families often shifted to driving partway and walked the rest. Some noted that public transport alternatives were too expensive or inconvenient, highlighting inequities in access to affordable, reliable alternatives to the car. Additionally, some reported traffic diverting around the ULEZ increased congestion in some surrounding areas, disproportionately affecting those living outside central London.
Teachers and parents noted broader social implications, such as improved lung health for children in more polluted areas and safer streets surrounding the school. However, participants also expressed concerns that the benefits of the ULEZ were unevenly distributed, with certain families better equipped to adapt by investing in cleaner vehicles or alternative travel modes like cycling.
This study highlighted the importance of ensuring accessible, affordable, and well-connected public transport, alongside improved infrastructure for walking and cycling alongside the ULEZ. When implemented effectively, initiatives like the ULEZ can help reduce air pollution and improve public health. However, without equitable access to alternative travel options, such policies risk deepening existing transport inequalities.
The findings provide valuable insights for cities considering similar schemes. Its further success depends on addressing socioeconomic and geographic disparities to ensure its benefits are shared by all.
Study : CHILL: Children’s Health in London and Luton