Electric buses reducing air and noise pollution in Oxford, research suggests

In 2023, a deal worth £82.5 million was agreed between Oxfordshire County Council, the government, Oxford Bus Company and Stagecoach to fund the fleet of new battery electric vehicles.

Provisional data suggests that bus fleet electrification has reduced roadside citywide nitrogen dioxide (NO2) concentrations across Oxford by an average of 10 per cent from 2023 to 2024, and up to 24 per cent in areas of high bus traffic such as St Aldates and High Street.

Air pollution is the largest environmental risk to health in the UK contributing to an estimated 30,000 early deaths each year. Exposure increases the risk of asthma, stroke, heart disease and lung cancer and is linked to adverse birth outcomes, diabetes, high blood pressure and dementia.

The transition from diesel to electric buses also cut roadside traffic related noise in central Oxford by an average of 5.1 decibels – comparable to the reduction in noise you would experience by moving three times further away from a road.

The analysis by the National Institute for Health and Care Research (NIHR) funded Public Health Intervention Responsive Studies Team (Universities of Birmingham, Warwick and Keele), in partnership with the University of Oxford, investigated air and noise pollution changes before, during and after the introduction of battery electric buses in Oxford. It also explored people’s experiences of introducing and using the new fleet, including key stakeholders, bus passengers, residents and commuters.

Professor Felix Leach, who led the study at the University of Oxford, says, “By using low cost noise pollution sensors, we were able to not only measure the reduction in noise emissions from the buses due to electrification but also the reduction in noise exposure for Oxford’s residents, which, combined with the air pollution reductions, leads to real health benefits for Oxford’s residents”.

Dr Suzanne Bartington, Clinical Associate Professor in Environmental Health at the University of Birmingham, says,“The transition to electric buses has had a measurable and meaningful impact on air and traffic related noise quality in Oxford. Importantly, we found that people noticed these changes – including less diesel fumes and fewer sleep disturbances, suggesting a real benefit for people’s lives.”

The zero emission bus regional area (ZEBRA) funding scheme is a national initiative contributing to transport decarbonisation and improved bus quality and provision. It has supported the deployment of over 4,000 zero emission buses in England since 2021.

In Oxfordshire, the county council contributed £6m and secured £32.8m from the Department for Transport. This was supplemented by £43.7m from the two commercial bus operators to support the introduction of 159 battery electric buses, across 34 routes in Oxford city centre and the surrounding areas, plus the Sightseeing buses.

At full implementation, electric buses account for 69 per cent of daily bus mileage within the city and 49 per cent of daily bus flow.

Councillor Andrew Gant, Oxfordshire County Council’s Cabinet Member for Transport Management, said: “We are proud and thrilled that we were able to back our ambitions with political and financial capital, alongside our partners, to deliver a safer, cleaner, greener, better county for residents and visitors. This provisional data shows what a difference these electric buses are making to people’s lives already.”

In Oxford city, air pollution has fallen in recent years but while legal limits are widely met across the city, levels still exceed World Health Organisation global air quality guidelines. Noise pollution has a direct impact on sleep and increased risk of heart disease, stroke, diabetes, depression and anxiety.