Developer Portal and API release notes

Release notes list all of the changes that are introduced by new release both to the Developer Portal and the hosted APIs. Use them to check for any known issues, and what changes you might need to make before you migrate your app to use any new version released.

2025-05 (4) - Data Services May 2025 Patch

This patch for includes minor performance across all the data services, including:

  • Developer Portal: API specification guidance updates and additional FAQs

  • Data services: Pagination refinement and other service backend optimisation

2025-01 (1.0) - Digital Variable Message Signs API

The Digital Variable Message Signs (DVMS) data service offers developers access to data regarding the messages displayed on electronic variable message signs along England's motorways and major A roads due to roadworks, incidents, or any other reason.
For the initial deployment, National Highways has excluded specific 'instructional' messages from the API's scope. This precautionary measure is directed to address risks associated with external organisations presenting conflicting directives to road users due to delays in processing National Highways data or latency issues.
It's important to highlight that the majority of non-instructional messages are included in the API feed, as they do not present the same risk when subject to transmission delays.

2025-02 (2.0) - Road and Lane Closures API v2.0 and Developer Portal updates

This new version of Road and Lane Closures provides the following new features:

  • Updated refresh cadence with updates from roadworks management systems occurring regularly throughout the day

  • Updated DATEX II payload re-aligned to v3.4

  • NOTE: this is a breaking change and applications will need mappings updated to process the payload

This patch also includes the following updates to the Developer Portal:

  • Updated look and feel to home page

  • Updated feedback mechanism to enable streamlined issue resolution

2025-02 - Diversion Routes Spatial Dataset released on National Highways Open Data Portal

National Highways has released a spatial dataset for diversion routes used to deal with emergency situations, the dataset is available from here (opens in new window)

2025-03 - Road Limits and Features API v1.0 released

A new data services is released, Road Limits and Features provides the following new information:

  • Emergency refuge areas across the Strategic Road Network (SRN)

  • Emergency telephone locations across the SRN

  • Bus stops situated on the SRN

Vehicle, access and turn restrictions are all shared as part of the National Highways Network Model that has been made public via the National Highways Open Data site.

2025-03 - Road and Lane Closures API v2.0 updates & Speed Managed Areas API v1.0 updates

Road and Lane Closures and Speed Managed Areas updates for unplanned closures and speed management is now available, this update provides the following new information:

  • Unplanned road closures as communicated by physical signs and signals across the SRN

  • Unplanned lane closures as communicated by physical signs and signals across the SRN

  • Unplanned advisory and mandatory speed limits implements for traffic management across the SRN via physical signs and signals