Department for Transport
Setting a world leading standard for digital road data
The UK Department for Transport (DfT) Digital Traffic Regulation Orders (D-TRO) programme is transforming how the local rules of the road are created, shared, and applied across the country. DfT’s task was to create a national digital service to capture and share the digitised outputs from a century-old, paper-based system for managing traffic regulation orders, and turn them into a single, reliable, machine-readable source of truth for road rules.
We designed and delivered a user-centred, API first service that has now been adopted nationally and is driving innovation in areas such as automated vehicles. The result is a world-leading platform that strengthens safety, improves data consistency, and benefits every road user.
Reimagining how the local rules of the road are created and shared
Traffic Regulation Orders (TROs) define much of what people encounter on the road, from where speed limits start and end to where vehicles can turn, stop, or park. For more than a century these rules existed only on paper, often still printed in local newspapers or pinned to telegraph poles.
As the UK prepares for autonomous vehicles, it's becoming clear that analogue data cannot deliver the precision, reliability, or scale that modern mobility demands. D-TRO set out to change this by creating an authoritative, digital, machine readable view of UK local road rules that mapping services, technology providers, and future vehicles could rely on. Importantly, D-TRO does not replace the legal or operational processes local authorities use to create traffic regulation orders; instead, it provides a central digital register that captures and standardises their outputs.
This is an important area for the future of the UK – we’re creating a single source of data truth that will secure the future of UK roads.”
Navigating the complexity of national digital change
The programme had to bridge two very different worlds: local authorities with long-standing paper-based processes, and digital consumers such as Google, Waze, and future autonomous vehicle providers who depend on clean, consistent data. Rather than replacing local authority systems, D-TRO created the central platform and standards needed for this data to be shared consistently at a national level.
Early requirements didn’t fully meet the needs of either group, and the inherited Alpha phase architecture required reassessment to understand whether it could deliver the robustness and scale required nationally.
It was this mix of strategic uncertainty and technical complexity that led DfT to choose us. We brought the combination of user-centred design, strong engineering capability, and experience delivering government services needed to turn an ambitious concept into a working national platform.
The department’s ambition to build a Google Cloud-based platform added further challenges, as many necessary data standards did not yet exist. They needed clear architectural direction, help navigating complex decisions, and confidence that the service would be secure, future-proof, and able to support a broad and evolving user community.
Embedding user insight into a data-only service
The greatest adoption challenge lay with local authorities, for whom engaging with a national digital register alongside existing legal processes represented a significant cultural and operational shift. Without an intuitive service, clear support, and ongoing communication, national implementation would have been at risk.
We applied user-centred design in a way rarely seen in purely data-driven, API first government services. Through extensive research with both publishers and consumers, we turned broad ideas into concrete, validated requirements. We then developed the data model and tested each iteration openly through a dedicated sandbox environment, enabling technology providers to integrate early, work with real data, and confirm that everything functioned end to end.
Putting users at the heart of a data service was new territory for government – but it’s what ensured the model works for both publishers and consumers.”
Building a secure and future-ready national platform
Our architecture and engineering teams worked closely with DfT to validate the inherited Alpha architecture and ensure it could scale effectively. We assessed whether the chosen Google Cloud services were appropriate, sustainable, and aligned with departmental standards. We then strengthened the platform with secure-by-design practices, including detailed threat modelling, to ensure it met the demands of a national-level digital service.
We also supported a largely non-technical client team, helping them build understanding of cloud technologies and giving them the clarity needed to make faster, more confident decisions.”
To maintain trust and momentum, we created regular webinars, online forums, and open documentation. These channels enabled DfT to explain upcoming changes, gather feedback, and co design improvements with users. Over time, this created a genuinely collaborative environment. As John Cooper, D-TRO Product Owner, Department for Transport, commented, “The dialogue with users has become genuinely two-way – they feel heard, and the service is better because of it.”
Achieving adoption, reducing costs, and setting global standards
The D-TRO service progressed through Private Beta, passed its Public Beta assessment first time, and is now used by more than 100 organisations. Over 100,000 digital TROs have already been created. The UK now leads internationally in establishing digital road regulation standards, influencing approaches emerging across Europe and the United States. The platform is enabling centralised access to consistent road data, and improving consistency and accessibility of traffic regulation data at a national level.
Most importantly, the service will enable organisations such as navigation providers and future mobility services to deliver safer, more reliable journeys for drivers, cyclists, and pedestrians. And as automated vehicles become more common, this foundational service will play a vital role in keeping the UK moving safely and intelligently.
PA didn’t just deliver a service – they helped us build confidence, capability, and a national platform that will shape the future of UK roads for years to come.”
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