Average speed, average delay and the reliability of travel times on Highways England’s motorways and ‘A’ roads are brought together in the along with the statistics on average speed and average delay on local ‘A’ roads are currently presented at national, regional and local highway authority level. In addition, national splits by urban, rural roads, peak and off-peak periods are also presented.
The statistical release for both sets of statistics are published on a quarterly basis (in February, May, August and November). Historically, these were published separately, with the first combined release for statistics covering up to the year ending June 2017. The supporting statistical tables for the local ‘A’ road statistics, by region and local highway authority are updated on an annual basis (in February). All other datasets are updated on a quarterly basis.
These statistics used to monitor road congestion and journey time reliability are compiled from journey time data from in-vehicle global positioning systems (GPS) and flows estimated using automatic traffic counters and the department’s manual traffic count data.
The road congestion and travel times statistics guidance contains a brief introduction into these statistics, including what they measure, how they are published and how they are used. The guidance also includes technical information relating to the reliability of journeys on the Highways England’s network and on locally managed ‘A’ roads, plus information on public attitudes and research and development.