The AIR Index helps policy makers improve air quality in towns and cities immediately by providing independent ratings based on the European CEN Workshop Agreement CWA 17379, the basis for a legal framework suitable for policy making.
This legal framework addresses the limitations of existing city policy as it provides a fair and comparative rating more accurate than existing Euro emissions standards. The existing standards are unable to provide a comparative and accurate measure of on-road vehicle NOx emissions. This has meant that until the Real Driving Emissions (RDE) legislation, for new models from September 2017 and all cars from September 2019, actual on-road emissions could not be implied from the Euro level. Consequently some policies are unfair to road users and have been unable to improve urban air quality.
The AIR Index provides a fair, standardised way of ensuring that low emitting cars are provided with access to cities and high emitting cars are either retrofitted or restricted. The AIR Index also provides independent proof of Euro 5 retrofitting effectiveness and the very low on-road emissions of RDE cars.
The results of independent on-road emissions testing reveal that some diesel engines actually produce lower NOx emissions than petrol engine variants and the AIR Index provides clarity, ensuring robust city policy to improve urban air quality quickly.
All cars tested for the AIR Index meet the European emission standards required at the time of delivery, such as Euro 4, 5 or 6. The AIR Index A-to-E rating provides a deeper, more realistic, independent assessment of the actual and relative emissions of each car.
The AIR Index is a global first. It is the only system that provides comparative emissions ratings based on standardised on-road testing. The AIR Index rating categorises vehicles in bands, based upon NOx emissions data measured during on-road tests. Testing each vehicle in urban conditions to the same test provides comparable NOx emissions levels that more accurately reflect the contribution to urban air quality than simulated tests performed in a laboratory. It also provides full comparability between vehicle makes and models, both new and old.
The data is publicly available, transparent and free of charge. Policy makers are offered access to the database via API to enable effective decision making to improve air quality.