Percentage of motorway and trunk road network requiring close monitoring of structural condition

Variable filters

You will be able to change the filter selections once you've chosen how to view the data.
Financial year
31 of 31 selected
No values match your search
Road class
2 of 2 selected
No values match your search
Work required
5 of 5 selected
No values match your search
Data description

This indicates what a data value represents

2 of 2 selected
No values match your search

Choose how to view the data

You'll be asked to choose 2 variables to show on a table
The data will be shown with columns for each of the variables in the dataset, with a data value for all combinations of variables

Next update expected:August 2027

Updates

13th August 2026

This update includes the publication of 2025-26 data.

21st January 2026
Dataset first published.

Main information

Designation
Official statistics
Data provider
Welsh Government
Data source
Road conditions of motorways and A trunk roads
Time period covered
April 1995 to March 2026
Dataset ID
f91da5a6-166a-4a90-b41e-6e7624a4953c

Overview

Summary of dataset and variables

Calculated using Deflectograph. The structural condition of a section of road is in need of close monitoring when it has a negative residual life. Figures are for the whole flexible network. Percentages may not add up to 100 per cent due to rounding. Excludes concrete pavements and elevated carriageways. Since 2015-16, figures have been calculated using Pandef processing software.

Data collection or calculation

Deflectograph surveys: Information on the structural condition of major roads is usually collected by means of Deflectograph Surveys. A Deflectograph is an automated technique for measuring the deflection of a road surface under a standard load. Software such as DEFLEC and PANDEF have been developed to allow the structural condition of the road to be derived from the measured deflections, given certain data about the construction of the road and about the traffic loading.

Statistical quality

In past years there have been two main methods of processing Deflectograph data. WG has made use of the Deflec method, which has processed all of the surveys up to 2014/15. This has become superseded by the Pandef method of processing.

This change in software has aligned the Welsh Government with the rest of the UK, including Highways England and Transport Scotland.

Related reports

Published by

Organisation
Welsh Government
Contact email
stats.transport@gov.wales