12 February 2015 - On the day The Infrastructure Act became law, The Department for transport highlighted what could be interpreted as a decline in performance of A roads in terms of congestion, reporting the average speed on local ‘A’ roads in England during the weekday morning peak in the year ending September 2014 was 24.1 mph, a 0.7% decrease on the year ending September 2014.
Increases in levels of traffic and intermittent periods of high rainfall levels were stated as likely to have contributed to the fall in speeds observed between March 2012 and December 2014.
Speeds are measured during the weekday morning peak as this is when demand on local ‘A’ roads is typically at its highest. This high demand often leads to physical congestion and low speeds.
London experienced the greatest fall in average speeds (4.5%) across all nine regions, that may be partly attributed to a reduction in speed limits in some London boroughs (e.g. the introduction of some 20mph zones to improve road safety).
DfT has been working with the Highways Agency and consulted with local authorities to develop new travel time measures for the strategic road network. It plans to publish statistics for the strategic road network on this new suite of measures later in 2015.
Reliability of journeys slightly better in 2014, but only due to drier weather late in then year
DfT also announced that the reliability of journeys on Highways Agency roads has been broadly stable since March 2013, with 2014 statistics on ‘reliability’ showing that 78.6% of journeys on the Highways Agency managed network between January and December 2014 were ‘on time’, a 0.3% increase compared to the year ending September 2014.
The annual reliability measure (percentage of journeys on time) increased from the year ending March 2011 up to March 2012, to a peak of 81.5%, but decreased in each of the following twelve months to March 2013. The changes in reliability over this period are believed to be predominantly due to large changes in rainfall and periods of heavy snowfall in England, relative to the previous year.
The reliability measure has been broadly stable since the year ending March 2013.
Towards the end of 2014, rainfall was lower in most months compared to the same months in 2013 which is thought to, at least, partly explain small increases in reliability since August 2014.
The Highways Agency’s network of motorway and ‘A’ roads accounts for around 2% of all roads in England, but carries around a third of all traffic.
The reliability of journeys on the Highways Agency’s roads is a measure of how predictable journeys are on the network. For the statistics in this release, reliability is measured
by the percentage of ‘journeys’ that are ‘on time’ where:
The data are based on journey times which are estimated using in- vehicle Global Positioning Systems (GPS) and traffic flows estimated using automatic traffic counters.
For further information, an introduction to the Department’s road congestion and reliability statistics is available.
DfT plans to cease production of statistics relating to the current ‘on time’ reliability measure after March 2015 data is published, in May 2015.
However, it intends to measure reliability and proposes to publish statistics on a new reliability measure later in 2015. These will be published as ‘Experimental’ statistics and will replace the ‘on time’ reliability statistics.
It intends to start publishing statistics on average speeds and congestion (measured by average delay) on the strategic road network (SRN).
The new reliability measure is known as the Planning Time Index (PTI). The PTI aims to measure the additional time that drivers need to leave to ensure that they arrive at their destination ‘on time’ most of the time (e.g. I need to leave an extra 20% of time - on top of the expected time under free-flow conditions - to arrive ‘on time’ most of the time).
These proposals were made following feedback from local authorities and other stakeholders, and work with the Highways Agency.
These proposed measures are aimed at “provide a more holistic evaluation of travel time performance on the SRN”.
Request for feedback
The DfT requested feedback from users of transport statistics in light of its planned changes to permanent use of its currently ’experimental statistics’. Comments are requested via the DfT Road congestion and reliability statistics enquiries email.
The DfT has also today published its Roads reform: final stage impact assessment related to its proposals for turning the Highways Agency (HA) into a government-owned company.
The government decided to reform the Highways Agency as its strategy document Action for Roads found that management of the strategic road network (SRN) created “cost-inefficiencies for the tax payer and does not deliver the best out come for road users.”
Reasons given for the change included “a lack of long-term certainty on investment in the network, a working culture dominated by the processes of wider government and no continuous external pressure for efficiency. A large increase in funding was announced at the last Spending Round so the Government wants to ensure the institutional framework for the management of the SRN is appropriate and maximises value for money”.