A smart motorway (formerly managed motorway) is a section of motorway in Great Britain that uses active traffic management (ATM) techniques to increase capacity by use of variable speed limits and hard shoulder running at busy times. Benefits include smoother traffic flow, more reliable journey times, fewer road traffic collisions, and reduced noise and harmful vehicle emissions. The term controlled motorway is sometimes used for schemes that use variable speed limits without hard-shoulder running (for example, the M25 from J27 to J30).
The technique was first used in the UK on the M42 motorway in the West Midlands in 2006. A higher speed limit of 60 miles per hour (97 km/h) was trialled on the southbound carriageway between junctions 4 and 3A from 2008 (a 10 miles per hour (16 km/h) increase on the previous maximum permissible speed).
In 2007 plans were announced to extend the scheme to two sections of the M6 near Birmingham (4-5 and 8a-10) by 2011 for £150 million. The emergency refuges were to be extended to every 800 metres (0.50 mi) on the roll out. A study into the use of ATM on the M1, M4, M20 and M25 motorways was also announced, however the Department for Transport had decided to proceed with a scheme to widen sections of the M25.
A £2 billion contract was announced to extend the scheme to sections of the M1, M4, M5, M6, M60 and M62 in February 2010 with a further announcement by the new government in October 2010. In March 2012 the government indicated that was considering a trial of higher 80 mph speed limit on some Managed Motorways although proposals for higher speeds on motorways were met with caution on a number of grounds by both motoring and road safety organisations.
This section needs to be updated.(May 2017)
Highways England (formerly known as the Highways Agency), Transport NI, Transport Scotland (who promote the technology as Intelligent Transport Systems) and Traffic Wales are responsible for the schemes in England, Northern Ireland, Scotland and Wales respectively. In the following table, schemes are classified into 3 types:
As of April 2016 the following schemes are operational, under construction or planned:
|M1||J10-J13||Dynamic hard shoulder||Operational|
|M1||J16-J19||All lane running||Operational|
|M1||J28-J31||All lane running||Operational|
|M1||J32-J35a||All lane running||Operational|
|M1||J39-J42||All lane running||Operational|
|M3||J2-J4a||All lane running||Operational|
|M4||J19-J20||Dynamic hard shoulder||Operational|
|M5||J4a-J6||All lane running||Operational|
|M5||J15-J17||Dynamic hard shoulder||Operational|
|M6||J4-J10a||Dynamic hard shoulder||Operational|
|M6||J11a-J13||All lane running||Operational|
|M25||J5-J6||All lane running||Operational|
|M25||J6-J7 counter-clockwise||Controlled motorway||Operational|
|M25||J6-J7 clockwise||All lane running||Operational|
|M25||J23-J27||All lane running||Operational|
|M5||J4a-J6||All lane running||Operational|
|M40||J16-M42 J3a westbound||Controlled motorway||Operational|
|M42||J3a-J7||Dynamic hard shoulder||Operational|
|M62||J18-J20||All lane running||Operational|
|M62||J25-J26||All lane running||Operational|
|M62||J26-J28||Dynamic hard shoulder||Operational|
|M62||J29-J30 eastbound||Dynamic hard shoulder||Operational|
|M62||J29-J30 westbound||All lane running||Operational|
|M90: M9||J1a-J3, including bus lane from J1a and J2a||Dynamic hard shoulder||Operational|
|M1||J23a-J25||Controlled motorway (J23a-J24)
All lane running (J24-J25)
|M6||J2-J4||All lane running||Construction|
|M6||J16-J19||All lane running||Construction|
|M23||J8-J10||All lane running||Construction|
|M27||J4-J11||All lane running||Construction|
|M25||J10-J16 (Upgrade of controlled motorway)||Planned|
|M42: M5||J4a-J3a(Birmingham Box: phase 4 smart motorway)||Planned|
The map to the right visually represents the operational and under construction elements of the UK's current smart motorway system.
The M42 scheme was initially run as an experiment and a Highways Agency report into the first six months of the scheme showed a reduction in variability journey times of up to 27%. The journey time statistics can be broken down to show that northbound journey times were reduced by 26%, equating to an average reduction of 4 minute as compared to the period when the variable speed limits were on but the hard shoulder was not being used and 9% southbound (equating to 1 minute) during the afternoon rush hour. The report also indicated a fall in the number of accidents from over 5 a month to 1.5 per month on average. The Agency did state that normally accident statistics should be compared over a 3-year period, so the initial results should be treated with caution. They also stated that no accidents had been caused by hard shoulder use as a normal lane. The report also stated that there had been a 10% fall in pollution and 4% fall in fuel consumption. The report also indicated a compliance rate of 98% to the indicated speed limits when using the hard shoulder. For comparison before the introduction of mandatory speed limits at road works, the compliance rate was 10% as opposed to 89% afterwards, showing a similar effect.
The Campaign for Better Transport argued that whilst it would reduce the need for widening schemes, it did nothing to reduce traffic and CO2 emissions. Friends of the Earth criticised the scheme as "widening on the cheap" and also pointed to a possible increase in vehicle emissions. Highways England argue that ATM reduces the environmental impact in regards to widening as it is carried out within the existing boundaries of the motorway as well as a possible improvement in local air quality due to smoother traffic flow.
The RAC cited a study in the Netherlands that showed drivers using the hard shoulder when they were not permitted, increasing the risk of a collision for vehicles stopped. The Royal Society for the Prevention of Accidents also expressed concern that emergency services would take longer to reach an incident. The Highways Agency rejected this concern based on the 5,000 miles of dual carriageway that does not have a hard shoulder. Disability groups were concerned that some drivers would not be able to access the emergency phones or even exit their vehicles, leaving them at increased risk. Ruth Kelly, former Secretary of State for Transport stated that these schemes were useful, but that motorway widening would still be considered where it was appropriate.
Road users will benefit from improved journey time reliability and safety as new congestion-tackling variable mandatory speed limits are introduced to maximise the benefits of the widened M1 in Nottinghamshire and Derbyshire from Wednesday 18 May 2011
Vehicles travelling on the busy 6.7-mile stretch of the M6 between junction 8 and 10A are now able to use the hard shoulder as a traffic lane during busy periods. This is the second successful section of hard shoulder running that consulting and business services Group Mouchel and contractor Carillion has supported the Highways Agency to deliver on the M6 in the last 18 months. This latest section follows the successful opening of the Managed Motorways scheme on the M6 between junctions 4 and 5 in December 2009.
The clockwise carriageway between junction nine at Leatherhead and junction 10 for the A3 will be closed from 2200 until 0600 BST on Sunday. The road has been closed each weekend since 29 January to allow installation of eight new overhead gantries. It is part of a project to extend the M25 controlled motorway system. The system, already in place between junctions 10 and 16, uses variable speed limits to reduce stop-start congestion during busy periods.