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Improving air quality across Birmingham

In October 2023, Birmingham City Council published the latest progress report on the performance of the city-wide Clean Air Zone (CAZ), looking at the impact that two years of operation has made on air quality and driver behaviour. Launched in 2021, the CAZ was developed and designed to reduce high levels of nitrogen dioxide in the air – and to do so in the shortest time possible.

Greg Allen, Director of Enforcement and EVCI at Yunex Traffic looks at the success of the Birmingham CAZ scheme and examples of other schemes where targeted interventions have successfully been implemented to address issues at a more local level.

You can read the Council’s report here, where you’ll see that the headlines tell a very successful story, with pollution levels across the CAZ having fallen by almost 40% since the scheme was first introduced. The top level results show that:

  • The levels of nitrogen dioxide in the clean air zone in 2022 were an average of 17% lower than in 2019.
  • When compared to 2016 (the year used in the original modelling for the CAZ), there has been a reduction in nitrogen dioxide levels of 37%.
  • The percentage of non-compliant vehicles entering the zone has reduced from 15.2% in June 2021 to 6.0% in June 2023, a reduction of 60.5%.

While the report contains overwhelmingly positive news, there are a couple of areas that the Council recognises need more work. These are two specific locations in the city (the Moor Street interchange and St Chads Queensway) where although the levels of nitrogen dioxide in the air are reducing, they are still over the legal limits. It’s in these situations where perhaps other, directly targeted interventions could be used to supplement the broader work that the CAZ is doing.

In these specific situations, there are a number of solutions that can help – the type of intervention very much depending on the nature of the problem. For example, intelligent traffic management and control solutions can set strategies at signalled traffic junctions that take into account the impact of air pollution. This could mean prioritising cleaner air outcomes, or alternatively public transport or active travel modes – depending on the desired goal.

To help Liverpool City Region Combined Authority achieve its air quality goals, we worked with our partner EarthSense to install air quality monitors on traffic signals on 37 corridors across the city’s key road network. Using innovative technology, these monitors measure particulate matter and gases (including NO2, NO, O3, PM1, PM2.5 and PM10) in near real-time and provide management and environmental reports.

The air quality data is integrated into our Stratos traffic management and urban traffic control systems to help manage traffic and avoid congestion by diverting motorists away from pollution-heavy locations when high concentrations of emissions are recorded.

The data produced enables trends in environmental data to be reviewed and analysed and will help the Combined Authority to set strategies based on real-time pollution, temperature and humidity data, as well as the prevailing air quality levels.

Now that authorities have the power under Part 6 of the Road Traffic Act to enforce moving traffic offences, it may also be that strictly enforcing yellow box junctions, banned right turns or bus lane use would also deliver improvements in air quality, by reducing congestion and improving traffic flow (as well as cutting journey times for road users). These ANPR-based solutions work alongside the CAZ and other location-specific interventions to improve air quality, help reduce carbon emissions and create a healthier, safer and more enjoyable environment for everyone.

In other targeted activity, Birmingham City Council has also already installed more than 15 School Streets schemes, specifically targeted at individual schools across the city. Part of the national Modal Stars initiative which encourages schools to promote active travel, School Streets use ANPR cameras to enforce the temporary closure of one or several roads around schools at drop-off and pick-up times. Only those who walk, cycle or have vehicle exemption permits are able to enter the zone during the times when the School Street scheme is active.

Nationally these schemes are increasingly being introduced around primary schools to not only reduce road danger, but also improve air quality in the immediate environs of the school. They positively encourage behavioural change, with shifts to walking and cycling leading to improved physical health and mental wellbeing.

The success of the Birmingham CAZ, together with results from School Streets programmes and targeted interventions that address moving traffic offences, all demonstrate the positive impact that well-designed schemes provide, delivering health, well-being and safety improvements for road users, and operational and performance benefits for network managers and operators. Yunex Traffic is proud to be delivering these schemes and to be contributing to improved air quality in cities worldwide.