Melina Zarouka, the Access Cluster Lead from POLIS, welcomed participants and opened the webinar, with Pedro Gomes, Clean Vehicles & Air Quality Cluster Lead, commenting on the political backlash Low Emission Zones have been facing recently, making their implementation difficult and jeopardising their continuity across time. The aim of the webinar was indeed to explore how POLIS member cities such as London, Brussels, and Antwerp have been able to proceed with the effective implementation of LEZs despite the backlash.

London’s approach to improving air quality in London: Expansion of Ultra-Low Emission Zones (ULEZ)

Laura Deyett, from Transport for London (TfL), presented the city's air quality strategies and their resulting benefits. London has tackled pollution through a broad set of policies, including Ultra Low and Low Emission Zones (ULEZ and LEZ), a cleaner bus fleet, zero-emission taxis and PHVs, Investment in active travel and electric vehicle charging infrastructure.

The LEZ was introduced in 2008, with ULEZ following and gradually expanding. ULEZ operates 24/7 (except Christmas Day), with charges for non-compliant vehicles. Implementation has been phased, with permanent and temporary exemptions (for example, taxis, military vehicles, disabled users, community transport, etc) and several reimbursement options to ease the transition.

A targeted scrappage scheme was launched in January 2023 to support vulnerable groups such as low-income residents, people with disabilities, charities and microbusinesses.

TfL also prioritised public engagement through consultations and multi-channel campaigns, using the feedback received to adjust policies and improve acceptance.

Yvonne Brown, also from TfL, mentioned the benefits of ULEZ, with the impacts having been published in periodic reports. The reports revealed that each ULEZ phase had distinct impacts, with compliance spreading from central London outward. Emissions from cars and vans in outer London have significantly declined following the London-wide ULEZ expansion, reaching 96.7%, up from 91.6% in June 2023 and 39% in February 2017.

Looking at concentrations, a no-ULEZ scenario has been created in order to compare against observed air quality monitoring data. Overall, the full suite of ULEZ policies has improved air quality.

One year after the all-London boroughs-wide expansion, roadside NO₂ concentrations were on average up to 4.8% lower than in a no-ULEZ scenario, without the London-wide ULEZ expansion. NO₂ levels are 27% lower across London and 54% lower in central London. Outer London now matches or exceeds the NO₂ reductions seen across the rest of England. The ULEZ one-year report is available here.

Some key lessons learned are that effective ULEZ requires a strong political commitment, with clear objectives and robust research, early public consultation and stakeholder engagement, strong public information campaigns (vital for pre-compliance), effective complementary or supporting measures (such as scrappage and exemptions), transparent reporting and ongoing evaluation. 

Evidence of LEZs from Brussels and Antwerp

Marianne Chagnon, from Health and Environment Alliance (HEAL), presented findings from a recent study on the health impacts of Low Emission Zones (LEZs) in Antwerp (2017) and in Brussels (2018). The study assessed how LEZs have influenced air pollution, health outcomes, and socio-economic inequalities. A scientific summary is available here.

One of the key findings is a clear reduction in pollution levels. Both cities experienced greater air quality improvements compared to others. In Brussels, lower socio-economic groups, the most deprived neighbourhoods in Brussels, which are the most polluted areas, saw a faster improvement in air quality for black carbon and NO2 emissions.

Health impacts are not evenly distributed across a city as socially disadvantaged population subgroups are most affected by environmental hazards, more exposed to air pollution and subject to greater health harm.

Based on these findings, researchers recommend that LEZ implementation should not be delayed or slowed down. Early public engagement is key; residents and civil society organisations should be consulted, involved, and well-informed throughout the process.

At the European level, the study calls for stronger financial support and better mechanisms for cities to share best practices in implementing LEZs.

Key takeaways

The discussion then focused on exemptions and support measures designed to help residents adapt to LEZs, highlighting the challenge of communicating these complex schemes clearly and effectively to the entire population.

Collecting data to assess the impact of LEZs has also been difficult in some cases. In London, for example, some enforcement cameras have been vandalised.

Limited financial resources, as well as fluctuating political support, have been pointed out as major obstacles for cities to implement LEZs over time, despite strong evidence of air quality improvements. In TfL's case, the political support was strong and a specific budget was implemented, which was key to its success.

These examples have inspired other cities, but the consensus was clear: without committed local political leaders, even the most evidence-based policies are difficult to implement.