Smart motorway

The traffic management technique, including hard shoulder running, was first used in its full specification in the UK on the M42 motorway in the West Midlands in 2006.[3][4] 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).[5]

In 2007 plans were announced by the then secretary of state for transport, Ruth Kelly, to extend the scheme to two sections of the M6 motorway near Birmingham (4-5 and 8a-10) by 2011 at a cost of £150 million.[6][7] The emergency refuges were to be extended to every 800 metres (0.50 mi) on the roll out.[8] A study into the use of ATM on the M1, M4, M20 and M25 motorways was also announced,[6] however the Department for Transport had decided to proceed with a scheme to widen sections of the M25.[9]

From 2013 the current term smart motorway was used by the Highways Agency (now Highways England) to promote the technology to road users.[10]

A £2 billion contract was announced to extend the scheme to sections of the M1, M4, M5, M6, M60 and M62 in February 2010[11] with a further announcement by the new government in October 2010.[12] The contract was awarded to four delivery partners Balfour Beatty, Carillion and joint ventures BAM Nuttall/Morgan Sindall Group and Costain Group/Serco.[13] In January 2012, Carillion won the contract for M6 junctions 5 - 8 near Birmingham for £126 million.[13]

In early 2018, the contracts previously awarded to Carillion were taken on by Kier, following the collapse of Carillion.[14]

A map of the UK's smart motorway system built from publicly available data of constructed and planned smart motorway systems.

The map to the right visually represents the operational and under construction elements of the UK's smart motorway system as of June 2017.[15]

In 2007 it was estimated that ATM could be introduced within two years at a cost of around £5-15 million per mile[16] as opposed to 10 years and £79 million per mile for widening.[17][18]

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%.[6][8] 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.[19] The report also indicated a fall in the number of accidents from over 5 a month to 1.5 per month on average.[6][8] 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.[19] The report also stated that there had been a 10% fall in pollution and 4% fall in fuel consumption.[6] The report also indicated a compliance rate of 98% to the indicated speed limits when using the hard shoulder.[19] 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.[20]

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.[6] 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.[21]

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.[18] The Highways Agency rejected this concern based on the 5,000 miles (8,000 km) of dual carriageway that does not have a hard shoulder.[22] 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.[22] 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.[18]

The scheme has attracted criticism from motoring organisations such as the AA, who in 2018 reported that many members were concerned that speed limits were being imposed without good cause in situations where traffic was light.[23] In response, Highways England stated that they had "started a comprehensive review of how variable speed limits are set, including the amount of time they are visible to drivers"[23].

In January 2020, it was announced that a review was planned after freedom of information requests showed that near misses had increased up to 20-fold, and that 38 people had died. The emergency refuge areas (ERA) were placed 500 metres (0.31 mi) apart on the M42 pilot scheme, but can be 2.5 kilometres (1.6 mi) apart on stretches of the M25. Only 9% of drivers feel safe while using smart motorways. Some of the extra capacity is negated by drivers terrified to drive on the inside lane and not using them. [24][25]

A BBC Panorama aired on 27 January 2020 accused smart motorways of being responsible for multiple deaths in the UK.

On 28 January 2020 Police Federation of England and Wales chief, reported The Times newspaper, John Apter said he did not "like the term 'smart motorways' because it infers they’re a good idea. They’re anything but" and "a recipe for disaster. It’s a death trap. It’s inherently dangerous and putting lives at risk."[26]

In January 2020, all Smart Motorways were put under review to address safety concerns and determine an action plan. No new Smart Motorways would open until this review was published. On the 12th March 2020, the review and action plan was published. It stated changes to the standards for new smart motorways (ones which had not started construction) such as a reduction from upto 1.5 miles to 1 mile between Emergency refuge areas (or other qualifying areas) and Stranded vehicle detection radars to be installed as part of the project. Other actions it required to be taken is for all Dynamic Hard Shoulder Motorways to be converted into All-Lane-Running by March 2025, Stranded Vehicle Detection radars to be installed on all Smart Motorways within 36 months & a potential national programme to install more ERAs on current smart motorways. [27]

Early systems used dot matrix signs on gantries to display short text messages, with smaller variable signs above each lane and to the sides of the carriageway. Current smart motorway systems often use the "MS4" sign type [28] which can include pictograms from the Traffic Signs Regulations and General Directions.

Highways England, the South Wales Trunk Road Agent (there are no motorways in North Wales), Transport NI (Northern Ireland) and Transport Scotland are responsible for the construction and maintenance of smart motorways in their respective countries.[29]

Controlled motorway

A section of controlled motorway on the M25 in Hertfordshire.

Variable speed limits with the hard shoulder operating as it would on a conventional motorway. They have most often been installed where a motorway has previously been widened but with a discontinuous hard shoulder to incorporate existing bridges, therefore using the hard shoulder as a running lane is ruled out. Existing gantries are upgraded to support signals capable of displaying a mandatory speed limit and speed cameras.

Dynamic hard shoulder

A section of motorway with dynamic hard shoulder on the M42 in the West Midlands. Under RIS2

Variable speed limits with the hard shoulder selectively opened as a running lane during periods when traffic levels are too high for only three lanes of running traffic. When activated, vehicles can use the hard shoulder as a running lane. All lanes are limited to a maximum of 60 mph, but these can be lowered further. Studies have shown that many users struggle to understand the complex signs and signals, which gave rise to plans in the mid-to-late 2020s to change the dynamic hard shoulder into a permanent running lane, thereby making these schemes all lane running.

All lane running

A stretch of the M25 in Hertfordshire, where the motorway operates as four-lane running without a hard shoulder between J23-27.

Variable speed limits with the hard shoulder removed and converted to a permanent running lane.

The following schemes are under construction:

• M1: J13-J16[61] (all lane running)

• M4: J3-J12[62] (part all lane running, part controlled motorway)

• M6: J2-J4[63] (all lane running) and J13-J15[64] (all lane running)

• M23: J8-J10[65] (all lane running)

• M27: J4-J11 (all lane running)
• M62: J10-J12[66] (all lane running)

• M42 ATM Monitoring and Evaluation - Project Summary Report