All supporting statistical tables are updated on a quarterly basis. For local ‘A’ road statistics, we provide statistics by region and local highway authority which are updated on an annual basis in February.
Statistics on travel time measures on the Strategic Road Network and locally managed ‘A’ roads from data provided commercially by Teletrac Navman. These are produced on a quarterly basis, as an annual report for the previous year in February and subsequent table updates in May, September and November.
Historically, we published separate statistical reports for travel time measures on the Strategic Road Network and locally managed ‘A’ roads. These were produced on a quarterly basis (in February, May, August and November). Following user feedback we decided to combine the statistical releases, with the first combined release published for the second quarter of data for 2017. From February 2018 onwards we no longer intend to publish quarterly travel time statistical reports. Instead, we will publish an annual report in February, although we will continue to update the supporting tables 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.