Monitoring by the Rail Safety and Standards Board (RSSB) has confirmed that air quality across Britain’s rail stations is generally good — and where improvements are required, targeted action is already underway. The findings come from the pioneering Air Quality Monitoring Network (AQMN), commissioned by the Department for Transport (DfT) to provide transparent, reliable insight into station environments for passengers.
Rail remains one of the UK’s lowest‑emission transport modes. According to government figures, the rail sector contributes just 4% of domestic transport NOx emissions, achieving a 39% reduction between 2013 and 2023. Government and industry partners continue to collaborate to further reduce rail’s environmental footprint.
Air quality has been identified by the UK Government as a key public health priority, with high concentrations of nitrogen dioxide and particulate matter linked to negative health impacts. To improve transparency, increase public confidence, and identify areas requiring further action, the DfT commissioned RSSB — the rail industry’s independent technical and standards body — to undertake detailed monitoring across the national network.
The AQMN is now the first and largest systematic air quality monitoring network on a mainline railway anywhere in the world. The programme focused on approximately 100 stations where passenger exposure could be higher. Results show that around 50 stations would benefit from an air quality improvement plan — and operators, supported by Network Rail and RSSB, have already begun implementing targeted measures.
It is important to note that AQMN data does not assess worker exposure, which is governed separately under dedicated workplace regulations.
Industry Actions to Improve Air Quality
The UK rail sector is already delivering a wide range of interventions, including:
- Continued DfT funding for the AQMN through to 2030 and commissioning the UK Health Security Agency (UKHSA) to undertake passenger exposure assessments.
- Accelerated introduction of newer, cleaner rolling stock as part of the transition to Great British Railways, replacing older diesel fleets.
- Establishment of an industry‑wide diesel idling focus group to reduce unnecessary engine use, following RSSB’s Idling Good Practice guidance.
- Deployment of new stop/start technology by one operator to reduce engine running in stations and on low‑power routes.
- Review and adjustment of idling policies across all diesel operators, with several already reducing engine run times.
- Timetable and dispatch modifications to minimise the duration of diesel idling at stations.
- Improved station ventilation and trials of innovative pollution‑reduction technologies, including filter columns and treated surfaces at sites such as Salisbury and Birmingham New Street.
- Investigation of alternative power sources for train preparation, reducing reliance on diesel for cold starts and presentation activities.
Rachael Everard, RSSB’s Director of Sustainable Development, said:
“Air quality matters; the air we breathe is important to our health and wellbeing and to passenger comfort. As an industry, we are committed to creating a railway that has a positive impact on local air quality.”
She continued:
“Our research is helping identify the minority of areas where air quality is an issue on our network. By proactively identifying these locations, rail can act and target improvements quickly. Out of more than 2,500 stations nationwide, 50 needed an air quality improvement plan, and operators are already putting those into practice.”
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