Data to enable the UK’s first Zero Emission Zone


Oxford’s Zero Emission Zone pilot required a unique approach to the use of data in order to be fair and meet its air quality objectives

Britain’s first Zero Emission Zone (ZEZ) pilot, created by Oxfordshire County Council, Oxford City Council and Conduent Transportation, went live in Oxford on 28th February 2022. Not only was this the first of its kind in the country, but it also required a unique approach to the use of data in order to make it happen. In January 2019, Oxford City Council and Oxfordshire County Council highlighted the need to tackle air pollution and set out proposals for a Zero Emission Zone. The authority called out nitrogen dioxide as the local air pollutant of most concern in Oxford, and the only pollutant for which European limits continue to be breached in the city. The UK Government’s Committee on the Medical Effects of Air Pollutants warn there is no safe level of nitrogen dioxide.
Oxfordshire County Council and Oxford City Council have been focusing on ways to reduce air pollution levels within the city for some time, having implemented a low emission zone for buses in 2014 and secured government funding to install cleaner bus engines. The ZEZ pilot and its expansion into a larger area offers the opportunity to ensure a further reduction in air pollution levels.
“It’s a complex and challenging task to permit certain vehicles to enter into specific areas of a city freely whilst identifying and charging non-compliant ones,” says Pete Stone, senior software architect at Conduent Transportation.
The system operates by collecting vehicle registration mark data via Automatic Number Plate Recognition (ANPR) cameras of vehicles entering the ZEZ and checking the vehicles emissions output (via multiple databases) against the rules set by the scheme to determine if a charge is payable.

Determining if emissions data is correct
The scheme is the first to use emissions data as a key driving factor focusing on the number of grammes per kilometre (g/km) of CO2 produced by each vehicle, not solely relying on the vehicle class or engine type. Rather than doing a simple look-up for the details of one vehicle, Conduent’s system compares the initial DVLA data to the engine type and uses much deeper logic, based on what is known about the vehicle, to determine whether the emissions data is correct. The system applies additional look-ups from multiple sources in order to build a complete picture of the vehicle, rather than just relying on one data source.  
“The key issue we found when creating the platform for the ZEZ in Oxfordshire was that key data, such as that from the Driver and Vehicle Licensing Agency (DVLA), wasn’t necessarily complete or totally accurate,” says Stone. “In several cases, older gas-guzzling Subarus had been classed as zero emission vehicles because of the way they were originally registered. So, in order for a ZEZ platform to function correctly, it needs to cross-reference multiple data sources.”

A logical vehicle checker
Conduent Transportation worked in partnership with Oxfordshire County Council and Oxford City Council to design a logical vehicle checker that considers data from multiple sources such as the DVLA, Ministry of Transport (MOT) and the UK Vehicle Data service (UKVD) to ensure the most accurate data is obtained. The system will also consider permit and exemption data enabling the authority to apply a charging structure that takes into consideration each user’s needs.
“It’s up to local authorities how they wish their pricing models to operate; they are all fully configurable,” says Stone. “Clients can set different thresholds, whether relating to emission status, CO2 emissions, vehicle class, emergency service status, residence permit data or parking permit status. Our approach is about bringing all these different sources of data together in one platform and using them in the best way for our customers. We’ve made sure to design the system with foresight that we can add in new data sources to the mix without too much effort.”

Managing vehicles individually
Going forward, Stone adds, data is the key to unlocking the ability to manage each vehicle on the network individually. “Over time, the quality of DVLA data improved, so we use that as our first source and then go to second and third sources, namely Driver and Vehicle Standards Agency (DVSA) and UK Vehicle Data (UKVD). Any other sources that have a good API interface can also be added, so if there are use cases that need slightly different data then we build in an access route for those. But the core data sources used by local authorities are free to access using the authority’s credentials. This is how we can ensure that our clients are getting best value for money.”
Oxfordshire County Council and Oxford City Council have worked closely together on planning for the scheme, engagement and communications to residents and partners. “Using an accurate and flexible platform like Conduent’s is one way to reassure citizens they are being treated fairly and reasonably,” says Stone.    
The platform offers multiple points of contact for drivers and a robust system of checks and balances, which updates in as “near to real-time as is humanly possible”. The latest system ‘lookups’ on payments, exemptions and tickets are always as up to date as possible.

The platform is adaptable and scalable for any particular use cases. As Conduent’s system is designed to carry out logical searches from multiple sources, it can also be used to facilitate schemes such as Clean Air Zones (CAZ), Low Traffic Neighbourhoods (LTNs), and School Streets, as well as other healthy neighbourhood schemes. Seamlessly tying together transport and parking solutions enables authorities to have a holistic approach to achieving their clean transport strategies and provides the flexibility to layer multiple approaches, ensuring the best solutions are achieved in each area.