Dr Magda Cepeda Zorrilla looks at Ultra-Low Emission Zones (ULEZ). What are the positives and negatives of ULEZ and what preparations do we need to make before we implement new zones?
To combat air pollution and encourage environmentally friendly travel options, the London Ultra Low Emission Zone (ULEZ) was introduced in April 2019. All roads within (but not including) the North Circular (A406) and South Circular (A205) were included in this initial phase of the ULEZ. The programme was extended on October 25, 2021, to cover all areas bordered by the North and South Circular Roads, but not the North and South Circulars themselves. Beginning on August 29, 2023, the ULEZ programme will now cover all boroughs of London.
The benefits of ULEZ
Installing ULEZ respond to the several benefits associated with these schemes such as:
- Combating climate change: ULEZ regulations promote the use of electric vehicles and low-emission transportation options, which can help reduce carbon dioxide (CO2) emissions from road transportation even though it is more difficult to measure greenhouse gas (GHG) reduction through ULEZ. But ULEZ may help persuade more people to utilise bicycles or other environmentally friendly forms of transportation, which can assist individuals reduce their personal emissions of greenhouse gases from commuting.
- Reducing air pollution: The programme can help in particular with pollutants like nitrogen dioxide (NO2) and particulate matter (PM) by imposing tight emission regulations for cars entering the ULEZ. Cumulatively since 2019, it is estimated the ULEZ led to nitrogen oxide (NOx) emissions from road traffic reducing by 13,500 tonnes across London over the four-year period compared with what they would have been without the ULEZ, a reduction of 23 per cent. Regarding fine particulate matter (PM2.5), cumulatively, emissions are estimated to have reduced by 180 tonnes across London since 2019, compared to without the ULEZ, a reduction of 7 per cent.
- Contribution to improved public health: Exposure to air pollution has a number of adverse effects, including harming the health of unborn children, delaying lung development in schoolchildren, and exacerbating asthma symptoms (see Table 1).
- Potential healthcare cost savings: Improved public health brought on by less air pollution may result in lower medical costs for fewer cases of respiratory and cardiovascular disorders. In the case of the expansion of ULEZ in London, it’s expected that it will save the NHS approximately £5 billion by 2050, avoiding 300,000 new cases of air quality-related disease and reducing hospital admissions.
Considerations for the expansion of ULEZ
Three considerations should be made when planning the ULEZ readiness of other areas:
- The potential financial effects on businesses and people. Low-income people and small businesses are burdened by the costs of upgrading or replacing automobiles for those that comply with the criteria.
- The potential is that socioeconomic inequality may worsen. Due to their inability to acquire compatible automobiles, some people are unable to enter particular places. However, there is a social justice issue with relation to the poorest Londoners and Londoners from ethnic minority backgrounds because, while having the lowest rates of car ownership, they suffer the most from the city’s toxic air. In London, only five per cent of the lowest-income population own a car yet they are around 10 per cent more likely to suffer from toxic air.
- Displacement of emissions. It may be possible to reduce local air pollution, but if emissions are diverted to locations outside the zone, it’s possible that local pollution will worsen in nearby areas.
Table 1. Summary of the health outcomes from air pollution
| Life stage | Heath impact |
| Pregnancy and birth outcomes | Foetal development; low birthweight; gestational age and pre-term births; miscarriage, sperm count and mobility. |
| The developing child: from birth, through adolescence | Lung growth; asthma; blood pressure; cognitive abilities; inattention and hyperactivity and mental health and illness |
| Adulthood | Early death; cardiac health; stroke; brain and mental health; respiratory health; cancer and multiple chronic illnesses. |
Source: Impacts of air pollution across the life course – evidence highlight note
ULEZ may not be equally effective in all areas as its impact depends on various factors, such as existing public transport infrastructure; availability and affordability of low-emission vehicles; willingness from individuals to change their behaviour. Also in the case of London, a study in 2021 suggests that a “ULEZ on its own is not an effective strategy to improve air quality – the case of London shows us that it works best when combined with a broader set of policies that reduce emissions across sectors like bus and taxi retrofitting, support for active and public transport, and other policies on polluting vehicles.”
ULEZ implementation from the transport perspective
To determine the readiness of other areas (including outer London) for the ULEZ implementation from the transport perspective we must examine three key factors: the existing transport infrastructure, the vehicle fleet composition and the public transport availability.
- Transport infrastructure
This relates to the availability of charging points for electric and alternative fuel vehicles. Diverse reports and studies consistently show that the lack of infrastructure provision is a concern for many consumers and is a main barrier to mass uptake, therefore efficient and sustainable charging infrastructure network is essential to achieve the transition to electric vehicles. To date in the UK there are 31,476 charging connectors at 11,274 locations – the majority (25%) of these are in Greater London.
2. Vehicle fleet composition
This plays a significant role in ULEZ readiness. Areas with a large number of older, high-emission vehicles may face challenges to transition to cleaner transportation options. Therefore, assessing the age and emission standards of the existing vehicle fleet is essential to estimate the feasibility of implementing ULEZ. Regarding electric vehicles, data shows that by the third quarter (July to September) of 2022, 14% of new car registrations in the UK were battery electric vehicles (BEV) with a further 5% being plug-in hybrid electric vehicles (PHEV).
3. Public Transport availability
Regions with well-developed public transport networks offer viable alternatives to private cars and encourage people to switch to greener modes of travel. Robust public transportation can help to reduce the dependence of high emission vehicles making the region more prepared for ULEZ. In London, the Mayor has announced transport improvements which include: the new Superloop bus network, which will connect outer London; a further 1 million km expansion of bus routes in outer London and plans for a new West London Orbital Overground service, however, this is subject to funding.
Combine ULEZ with a range of transport policies
In conclusion, the implementation of the ULEZ in the UK has shown positive effects on the reduction of air pollutants, and even though it is difficult to calculate the reduction of GHG, the policies encourage the adoption of cleaner transport options.
However, when evaluating the readiness of other regions to adopt ULEZ or extending the scheme in outer London, it is important to consider that the ULEZ is ineffective on its own and that it is most effective when combined with a broader set of policies that reduce emissions across sectors, including support for walking and cycling, improving public transport, and other policies on polluting vehicles. Also, careful planning and coordination are essential to prevent unintended consequences from the ULEZ. And finally, supporting businesses and individuals in their move to cleaner technology is also necessary.
This blog was written by Dr Magda Cepeda Zorrilla, Research Fellow, City-REDI / WMREDI, University of Birmingham.
Disclaimer:
The views expressed in this analysis post are those of the authors and not necessarily those of City-REDI, WMREDI or the University of Birmingham.