Road transport emissions and activity data for the UK major road network

Hot exhaust emissions and the related fuel consumption estimates are calculated within the NAEI using fuel consumption and emission factors for each vehicle type.

These in turn are calculated on the basis of the composition of the vehicle fleet (age profile and fuel mix). The resulting fuel consumption and emission factors are applied to detailed spatially resolved traffic movements. In addition the fleet mix varies by location and as a result different emission factors are applied to different road types in different geographical areas. Vehicle fleet age profiles and fuel mix are fixed at a national level.

Fuel consumption factors and emission factors combined with traffic data for 6 major classes of vehicles are used to calculate national fuel consumption and emission estimates for passenger cars, light goods vehicles (LGVs), rigid heavy good vehicles (HGVs), articulated HGVs, buses/coaches and mopeds/motorcycles. The vehicle classifications are further sub-divided according to fuel type (petrol or diesel) and the regulatory emission standard the vehicle or engine had to comply with when manufactured or first registered.

The base map of the UK road network used for calculating the hot exhaust road traffic emissions is derived from the Ordnance Survey Meridian 2 dataset. This provides locations of all roads (motorways, A-roads, B-roads and minor roads) in Great Britain. In addition, a dataset of roads in Northern Ireland was obtained from the Land & Property Services which is responsible for all Ordnance Survey of Northern Ireland. The traffic flow data is available on a census count point basis for both GB and Northern Ireland. However, the coverage in GB is considerably denser than that for Northern Ireland, although some new NI count points become available every year.

Get data

Road transport emissions data are included as a separate layer in the UK emissions maps.  These can be downloaded from the UK Emissions Interactive Map.

Road transport energy data, mapped to Local Authorities are available for download from the DESNZ website.



Published: 12 January, 2024

Last updated: 18 July, 2024