Cambridge, September 5, 2024 — The introduction of the Ultra-Low Emission Zone (ULEZ) in Central London has significantly influenced children’s travel habits, leading to notable health benefits, according to new research from the University of Cambridge and Queen Mary University of London.
The study, published today in the International Journal of Behavioral Nutrition and Physical Activity, reveals that nearly 40% of children in Central London who previously traveled to school by car have switched to more active forms of transportation such as walking, cycling, or public transit following the ULEZ’s implementation. In contrast, only 20% of children in Luton, a comparison area without ULEZ, made a similar shift.
Car travel, a major contributor to air pollution, poses severe risks including respiratory issues and limited physical activity opportunities for children. The ULEZ, introduced in April 2019, aimed to curb these risks by reducing emissions from vehicles that do not meet strict environmental standards. Transport for London reported a 35% reduction in nitrogen oxides and a 15% decrease in particulate matter in the ULEZ zone within the first ten months of its launch.
The research, part of the CHILL (Children’s Health in London and Luton) study, analyzed data from approximately 2,000 children aged six to nine across 84 primary schools in London and Luton. The study compared schools within and bordering the ULEZ with those in Luton and Dunstable, enhancing the reliability of its findings.
Data collected before and after the ULEZ implementation shows a substantial increase in active travel among children in London. Prior to the ULEZ, 42% of car-traveling children in London shifted to active modes, whereas only 5% switched from active to inactive modes. Conversely, in Luton, just 20% of children moved from car travel to active modes, with 21% transitioning from active to car travel.
The impact was most pronounced among children living more than half a mile from school, likely due to their greater potential for changing travel habits compared to those living closer.
Dr. Christina Xiao, the study’s first author and a visiting researcher at the University of Cambridge, highlighted the dual benefits of the ULEZ: “Given children’s vulnerability to air pollution and the essential role of physical activity in their development, financial incentives against car use could foster healthier travel habits.”
Dr. Jenna Panter, a joint senior author from the MRC Epidemiology Unit, added, “Our previous government aimed to boost walking to school by 2025. We hope the current administration will continue this commitment. Promoting active travel not only enhances physical activity but also alleviates congestion and improves air quality, as a significant portion of peak-hour car trips in London are school-related.”
Following the ULEZ’s introduction, the total number of vehicles on London’s roads decreased by 9%, and the number of non-compliant vehicles fell by 34%, without noticeable traffic displacement to neighboring areas.
Professor Chris Griffiths, joint senior author from the Wolfson Institute of Population Health at Queen Mary University of London, emphasized the importance of early healthy habits: “Our study’s robust design underscores the ULEZ’s effectiveness in promoting active travel. This evidence supports the notion that Clean Air Zone interventions can enhance public health by mitigating major illness contributors.”
Although the study was paused during the COVID-19 pandemic, the researchers believe the initial findings remain valid. The study will resume tracking the children to assess the ULEZ’s longer-term effects.