Zero Emission Bus Regional Area (ZEBRA) scheme: The Introduction of zero-emission buses in Oxford

How are the public involved in the evaluation?

PHIRST PHRESH have an established Public Advisory Committee who advise across all our projects.  Alongside Oxfordshire County Council, we are asking existing local community and public representative groups to advise on and help with the design and delivery of the evaluation. Two members of the public are part of the evaluation project working group. One is a member of the PHRESH Public Advisory Committee, and one is a local resident in Oxfordshire. Through their membership of the project working group, they will contribute to developing the overall study design, informing recruitment methods, assisting with data collection, and interpreting and communicating the findings. 

Lay summary of research

The transport sector makes a big contribution to air and noise pollution. Air pollution is a problem for public health as it can lead to childhood asthma, and lung cancer, emergency hospital visits and early death in adults. Noise pollution can affect hearing, worsen chronic conditions such as heart disease and affects mental health. Replacing older diesel vehicles with electric ones is a way to drastically reduce or remove harmful air pollution and reduce noise pollution. Replacing diesel buses with electric buses may affect bus drivers, bus users and people who live along bus routes. There is not much research on how switching to electric buses impacts the health of people living and travelling in the cities.  

In Oxford, similar to many cities, air pollution is a public health concern, with levels that are harmful to human health. The national and local government and local bus companies have given money to replace 159 diesel buses with electric ones by November 2024. These buses are used along 34 routes serving Oxford and surrounding communities. The aim is to improve air and noise quality as well as reduce traffic levels and congestion in the city. The buses also have updated features that include new road safety features, bus stop announcements and display screens and more wheelchair space.  

What will we do?  

 We have worked with staff at Oxfordshire County Council and Oxford City Council as well as bus providers and members of the public (including bus users) to develop the research and will continue to work with them throughout the project. The specific objectives of the evaluation are:  

1. To assess the direct health benefits of the ZEBRA scheme, including impacts of air and noise pollution changes across the defined area.  

2. To understand the impact of the ZEBRA scheme on the travel preferences and behaviours of residents, commuters and visitors.  

3. To identify and explore (where feasible) the wider indirect impacts of the ZEBRA scheme, such as economic, social and technical implications, including unintended consequences.  

4. To understand experiences of ZEBRA scheme implementation, including barriers and enablers to full adoption.  

5. To explore the costs of the scheme from both LA and societal perspectives and consider the feasibility of a longer-term economic evaluation.  

6. To support relevant research skills and infrastructure development within OCC to enable long-term ZEBRA scheme monitoring and evaluation. 

How will we do it?  

We will investigate how introducing electric buses has influenced levels of nitrogen dioxide. Nitrogen dioxide is one of the main gases that contributes to air pollution. We will measure nitrogen dioxide using existing monitors that have been in place across Oxford for 10 years. This will enable us to look at how the levels of nitrogen dioxide have changed over time. We will compare this air pollution data with health information of children and adults in Oxford. We will look at the rates of asthma in children and adults, lung cancer, emergency hospital visits and early deaths in adults.  

We will measure levels of noise pollution along key city centre bus routes using small recording devices attached to lampposts for a two-month period before electric buses are introduced and again for a two-month period after fleet rollout.  

We will assess costs of the scheme and explore monetary benefits, including health and social savings arising from reduced air and noise pollution among those living in the city region.  

We will speak with key people within the bus companies and local authority to learn more about how the scheme is rolled out. This includes any other challenges that the bus companies or local authority faced when replacing the diesel buses. We will speak with people living in, travelling to, and visiting Oxford by organising focus groups and speaking to people at bus stops. We will ask them how they think the scheme has impacted air and noise pollution as well as wider impacts on the city, travel, the local economy.  

What will we do with the results?  

We will share our findings with local authority partners and bus operators to help shape future delivery of the ZEBRA scheme. We will also share our finding with public groups who have taken part in the research through a range of creative outputs and activities. 

The findings from this study will be useful for OCC staff to continue monitoring of the ZEBRA scheme and sharing the lessons with other areas that are implementing similar schemes.