Vehicle Emissions Data – Major Urban Areas

Vehicle Emissions Data – Major Urban Areas

Contract Capture of vehicle registration data and extraction of emissions class and other vehicle characteristics.
Service Advanced Automatic Number Plate Recognition (ANPR)
Scale Multiple sites across three major city centres
Project Location Three city centres with Clean Air Zone proposals
Audio Transcription for BBC Radio 4

“The data captured, analysed and reported by Tracsis allows clients to establish base line emissions levels at specific sites and across a city boundary to inform the development of Clean Air Zone strategies for their respective cities.”

Paul Jackson

Business Development Director, Tracsis Traffic and Data Services

Air pollution from road vehicles in major urban areas is a serious issue and whilst significant progress has been made in controlling emissions, the Environmental Audit Committee released a report showing that in 2013, only five out of 43 clean air zones in the UK met EU standards on levels of NOx.

In response, the Government announced in December 2015 plans to improve air quality in cities. Under these plans Clean Air Zones will be introduced in Birmingham, Leeds, Nottingham, Derby and Southampton by 2020 with other local authorities also able to introduce Clean Air Zones. These Zones will see the most polluting vehicles, like old buses, taxis, coaches and lorries, discouraged from entering the zone through charges. The plans set out a comprehensive approach by introducing targeted local measures to tackle the most polluting vehicles in a small number of air quality hotspots, alongside national action.

Vehicle emissions data can be captured using a variety of roadside pollution sensor techniques such as diffusion tubes, particulate and other pollutant sensors. This equipment is however very expensive and fixed in location requiring mains power supplies or if portable, it can be difficult to calibrate to a sufficient level of accuracy. To assess emissions for Clean Air Zone studies a technique is required which can establish emission levels at specific points along the road network capturing data in a way which can be analysed at aggregate or disaggregate levels.

Tracsis worked with the clients and determined that the most effective technique was the deployment of Tracsis Advanced ANPR camera systems to capture vehicle registration details at specified sites around each city centre. The registration number data were then fed through a database system to affix detailed vehicle data to each record. This data was aggregated from the DVLA, manufacturer databases and other automotive industry sources which ensured it is significantly more complete than just the DVLA dataset alone, especially on the Euro Emission Class field. As well as allowing the automatic and accurate classification of vehicles to the traditional classes of Car, LGV, OGV1, OGV2 and PSV this also allowed for the provision of a dataset which includes:

  • Date of vehicle registration
  • CO2 Emissions
  • Fuel Type (including electric and hybrid vehicle types)
  • Euro Emission Classes
  • Type Approval Category

Where data is incomplete in the source databases (which is common for the Type Approval and CO2 Emissions data from the DVLA) Tracsis have techniques to infer the missing data with a high level of confidence.

Through deep interrogation of the datasets, Tracsis were also able to identify repeat journeys by specific types of vehicles such as buses and taxis, allowing targeted emission control measures to be formulated.

Aside from the Vehicle Emissions Data there are also fields relating to vehicle weight (available for most vehicles except motorcycles and taxis), vehicle width and vehicle height. These fields were of interest for other client applications such as for road space design, weight restriction, etc.

With Tracsis’ Advanced ANPR systems we capture multiple lanes with each camera and achieve a sample rate of above 90% even in poor weather conditions. The read accuracy of the cameras is proven to be above 95% ensuring that the expanded data received back from the database systems is very accurate.

Across all three cities over 1.5 million vehicle registration plates were captured, processed and emissions data and fleet composition data extracted.


Despite challenging environments, the capture rate was in excess of 90% giving high confidence in the accuracy of the data.



The data captured, analysed and reported by Tracsis allowed clients to establish base line emissions levels at specific sites and across the City boundary as a whole to inform the development of Clean Air Zone strategies for their respective cities. Tracsis will be undertaking ongoing monitoring of emission data as the strategies progress.

Tracsis continue to advise local authorities on the use of the most effective techniques to establish Vehicle Emissions Data utilising both in-house system development expertise and expert consultancy advice.

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