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Air Quality

Clean air is important for both human health and the health of the environment.. Despite air being cleaner now than at any time since the industrial revolution, air pollution is currently estimated to reduce life expectancy of every person in the UK by an average of 7-8 months.

Dealing with Air Quality within the Highways Agency

Traffic using our road network  releases  pollutants into the air  which can affect  air quality and potentially affect human health and habitats, within 200m of a road. If people are likely to be exposed to pollution concentrations that exceed the Government's targets as set out in the Air Quality Strategy, then the local authority must declare an Air Quality Management Area and prepare an Action Plan to the situation. If the Air Quality Management Area is near one of our roads, then we work with the local authority in preparing that plan.We can  influence the effect on air quality of our activities and those of travelers using our network  through:

• Contributing to strategic planning;
• Road improvements; 
• Integrating transport and encouraging sustainable travel; 
• Providing better information for improved operation; and 
• Working with local authorities to deliver the Air Quality Strategy.

 We assess the environmental impact, including that on air quality, of all our improvement works to reduce or eliminate any adverse effects. For example see M25 Junction 16 to 23 Widening project. In most cases our road schemes are designed to relieve congestion on the roads so enabling traffic to flow much more smoothly.  As a result engines are used more efficiently and this ultimately reduces the amount of emissions released. We have made the commitment that we will not progress a road scheme which would worsen the air quality situation overall regarding compliance with the air quality limit values set by the European Union.

As part of our influencing travel behaviour work where we implement travel plans, we are giving priority to those sites with known air quality issues. Smaller schemes are also being given enhanced priority if they are expected  to deliver improvements in air quality.

We have a large air quality research programme to help us develop technical guidance so that we can carry out better assessments of our schemes, measure pollutant concentrations near our roads and assess the effectiveness of mitigation measures.  Current projects include revising the Design Manual for Roads and Bridges 11.3.1,  measuring  nitrogen dioxide in Air Quality Management Areas,  measuring long term trends in pollutant concentrations, improving emission estimates by considering instantaneous emissions and assessing the effectiveness of a NOXer  environmental barrier.

We will be continuing to seek opportunities to implement projects that reduce emissions in Air Quality Management Areas (AQMAs). This will also support the delivery of the Public Service Agreement target for air quality. (See section 3.27 for Department for Transport commitments PDF 348KB)

Additional Information

• Air Quality Management Areas located along the Highways Agency network, 2007
• The Role of the Highways Agency in Local Air Quality Management, 2003