Road Traffic and Congestion in Great Britain: Quarter 3 2008

This statistical bulletin includes statistics on Road Traffic and Congestion in Great Britain Q3 2008 according to arrangements approved by the UK Statistics Authority. This bulletin includes first release of the following National Statistics: 

• Provisional estimates for road traffic in Great Britain for the third quarter of 2008
• Provisional estimates for inter-urban congestion in England for the year ending September 2008

Road traffic in Great Britain 

The 2008 quarterly traffic estimates are provisional. The provisional figures show a decrease of 2.2 per cent in overall estimated traffic levels between the third quarters of 2007 and 2008.

The bulletin includes breakdowns by vehicle type and road class. Key results include:

• Car traffic decreased by 2 per cent
• Light van traffic was unchanged
• Heavy goods vehicle traffic decreased by 4 per cent
• Traffic on motorways was decreased by 2 per cent  
• Traffic on rural 'A' roads decreased by 3 per cent 
• Traffic on urban 'A' roads decreased by 2 per cent
• Traffic on both rural minor roads and urban minor roads decreased by 2 per cent

Provisional 2008 quarterly figures are likely to differ slightly from the final figures which will be published in August 2009. 

Inter urban congestion in England 

This quarterly bulletin also includes National Statistics on congestion on motorways and trunk roads in England used to monitor the PSA measure on inter-urban congestion. Between the CSR07 baseline year ending March 2008 and the year ending September 2008, provisional figures show that:

• Average vehicle delay on the slowest 10 per cent of journeys fell from 3.95 to 3.67 minutes per 10 miles.

Congestion in major urban areas in England

It has not been possible to include updated tables in this bulletin because of significant data problems found just before publication. It is planned to publish data for the year ending August 2008 with the monthly inter-urban release on 4 December.

Notes

Road traffic in Great Britain 

1. The quarterly estimates are based mainly on data from 180 Automatic Traffic Counter (ATC). Caution should be taken in drawing conclusions about longer term trends from the estimates for a single quarter or year.

2. The 2007 annual 'light van' and 'bus and coach' traffic estimates have been revised, leading to small changes from the quarterly estimates published in the previous addition of the bulletin. 

3. The final annual road traffic estimates are calculated from data collected by both the ATCs and 10,000 12-hour manual counts, combined with road lengths. Final annual traffic estimates for 2007 were published in the Statistical Bulletin Road Statistics 2007: Traffic, Speeds and Congestion, in July 2008. This bulletin can be found at http://www.dft.gov.uk/pgr/statistics/datatablespublications/roadstraffic/speedscongestion/roadstatstsc/roadstats07tsc   

4. The figures on traffic levels are measured in terms of vehicle kilometres and are sometimes known as the volume of traffic. This is not the same as congestion. For example, traffic levels could increase without increasing congestion if traffic is more evenly spread during the day, with less during peak periods and more at other times.

Inter urban congestion in England 

5. The indicator used to monitor inter-urban congestion is the average delay in minutes per 10 miles (derived from the differences between observed journey times and a reference journey time) experienced on the slowest 10 per cent of journeys for each monitored route. Currently, because of data quality considerations, 91 of the 103 routes are used to monitor network performance. More information can be found at: http://www.dft.gov.uk/pgr/statistics/datatablespublications/roadstraffic/speedscongestion/congestiononthestrategicroad5359

6. The data quality for the routes is reviewed every six months. In the next quarterly publication, some changes will be made to the routes included in the measure. The previously published data for years ending March 2008 - September 2008 will be revised leading to a small discontinuity with earlier years.

7. This indicator is one of four used to measure success against the Department's current Public Service Agreement (PSA) to deliver reliable and efficient transport networks that support economic growth. The indicator will be monitored from the baseline year ending March 2008 up to the year ending March 2011. Reliability performance will be assessed in the context of an expected increase in traffic of 1-2% per year. There is no specific numerical target. 

8. The data for September 2008 are provisional because there has not been full quality assurance at a route level, but it is unlikely that they will be revised. Provisional data for October and November 2008 will be published on 4 December and 2 January 2009 respectively.  

9. Due to an error in loading the August data for processing, revised data have now been issued for the year ending August 2008. All other rolling year data are unaffected. 

Publication details

Published on 6 November 2008 by Transport Statistics.

The next bulletin in this series will be published on Thursday 5 February 2009.

Email: roadtraff.stats@dft.gsi.gov.uk for queries concerning this publication.

For information about release of this product see National Statistics Online