The strategic road network includes motorways and ‘A’ roads that are managed by the Agency.
These strategically important roads account for around 2% of all roads in England, but carry around a third of all traffic.
The reliability of journeys on the Highways Agency’s roads is measured by the percentage of journeys that are ‘on time’, where: A ‘journey’ represents travel between adjacent junctions on the network.
An ‘on time journey’ is defined as one which is completed within a set reference time, based on historic data on that particular section of road.
The data is based on journey times estimated using in-vehicle global positioning systems (GPS) and flows estimated using automatic traffic counters.
This reliability measure is one of a number of indicators in the Department’s business plan.
The key findings include:
- In the year ending March 2013, provisional data shows that 77.1% of journeys on the Highways Agency managed network were ‘on time’. This is 0.5 percentage points lower than the previous year, ending February 2013.
- The annual reliability measure consistently increased up to March 2012, but has fallen in each of the last 12 months.
- Provisional data show that 77.7% of journeys on the Highways Agency network during March 2013 were ‘on time’, down 6.2 percentage points from March 2012.
The DfT has also released statistics that show road traffic estimates for Great Britain in the first quarter of 2013 and congestion on local authority managed 'A' roads from January to March 2013.
A range of commentary, tables and data on statistical trends in transport can be accessed by clicking here.