Change of https://www.gov.uk/government/publications/road-congestion-and-travel-times-statistics-guidance

Change description : 2025-10-02 09:30:00: Data imputation up to June 2025 added to local a quality table. Pre-release access list updated. [Guidance and regulation]

Showing diff : 2025-08-07 22:55:44.080733047 +00:00..2025-10-02 08:31:30.436695985 +00:00

Guidance

Road congestion and travel time statistics information

Guide to road congestion and travel time statistics, their source documents, notes and definitions plus supporting technical documents.

Documents

Details

Tables displaying the level of imputation for historic data tables CGN01, CGN02, CGN09 and select CGN04 and CGN05 are no longer available, as the relevant tables are no longer produced.

Road congestion and travel time statistics notes and definitions and other source documents.

Updates to this page

Published 11 August 2016
Last updated 252 JuneOctober 2025 + show all updates
  1. Addition of data for January to March 2025 to local a data quality table.

Sign up for emails or print this page

Update history

2025-10-02 09:30
Data imputation up to June 2025 added to local a quality table. Pre-release access list updated.

2025-06-25 20:55
Addition of data for January to March 2025 to local a data quality table.

2025-03-06 09:30
Data added to include information up to December 2024.

2024-12-05 09:30
Data up to September 2024 has been included in the ‘Percentage of data imputed for travel time statistics on the local ‘A’ road network, by month’ table.

2024-10-03 09:30
Data for April to June 2024 have been added to the ‘Percentage of data imputed for travel time statistics on the local ‘A’ road network, by month’ table, and revisions have been made to the series following agreements with suppliers to improve consistency going forward.

2024-06-27 09:30
Data up to March 2024 has been added to the Local A data quality table.

2024-03-07 09:30
Over 2023 the congestion statistics processing was transferred to a new software enabling greater precision and accuracy in calculations and imputation of the production of statistical values. This has led to minor revisions for ‘Percentage of data imputed for travel time statistics on the local ‘A’ road network, by month’

2023-12-13 09:31
Data table for the percentage of data imputed for travel time statistics on the local ‘A’ road network, by month has been updated.

2023-06-14 09:30
The percentage of data imputed for travel time statistics on the local ‘A’ road network, by month’ table has been updated to include data from April 2022 to March 2023.

2023-03-09 09:30
The ‘Percentage of data imputed for travel time statistics on the local ‘A’ road network, by month’ table has been updated to include data from January 2019 to December 2022

2022-12-14 09:30
The local A road imputation table has been updated to included data to September 2022.

2022-09-08 09:30
The ‘Percentage of data imputed for travel time statistics on the local ‘A’ road network, by month’ has been updated to include data to June 2022.

2022-06-29 09:30
A new HTML document discussing the impact of the coronavirus (COVID-19) pandemic on flow weighting has been added.

2022-03-16 09:30
A new background quality report has been produced to reflect the change in data suppliers and data processes.

2022-03-02 09:30
Percentage of data imputed for travel time statistics on the local ‘A’ road network, by month data table updated.