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Smart motorways – anything but clever?

Smart motorways have been in the news again after a tech failure left broken-down drivers marooned in live traffic lanes 'like sitting ducks'.


Smart motorways have been in the news again in the last few weeks, after a software failure in late February left broken-down drivers on multiple motorways marooned in live traffic lanes ‘like sitting ducks’, according to motoring groups.

The issue caused all signs and speed limits on overhead gantries to freeze and, crucially, disabled essential detection systems. These alert motorway authorities to stopped vehicles and close the lane that they are on. It affected stretches of the M1, M5, M6, M60 and M62 motorways.

It’s the latest setback for the smart motorway concept, which is facing a growing tide of anger from motorists who claim their lives are being put at risk by the supposedly congestion-easing technology.

Some fatal accidents have been directly blamed on the smart motorway system and, early in 2021, the government responded by promising no new smart motorways would be built until new safety technology was put in place. But worryingly there is now also evidence of the criteria for this technology being changed, with no commitment to the new tech working properly once it is installed.

It all sounds pretty grim for the smart motorway concept, so should we be avoiding them whenever possible? The Car Expert sets out to find answers…

Three kinds of smart motorway

Firstly, what exactly is a smart motorway?

The technology was born from the ever-growing issue of congestion on the UK’s motorway system – no matter how many extra lanes were added to major routes such as the M25, they quickly filled up with traffic, while drivers sitting in queues looked enviously at the empty hard shoulders bordering each road. The response has been to create what are three different types of ‘smart’ motorway.

All three are controlled by variable speed limits displayed on overhead gantries – these made their debut around the turn of the millennium, the concept being to slow traffic generally in times of high use, or when there was an incident so that traffic flow was managed more effectively, leading to less congestion.

Today, stretches of motorway that retain the hard shoulder as only somewhere to pull over onto in an emergency, are known as Controlled Motorways. You can usually tell you are entering one of these when you see a large blue sign alerting you that a ‘Variable Speed Limit begins’ and then the overhead gantries.

Having introduced the variable speed limits, the planners then focused on that strip of hard shoulder, which rarely had anything on it, as a greater opportunity. Strengthening said hard shoulder enabled it to be opened as a running lane in times of high congestion. This concept, known as a Dynamic Hard Shoulder system, was first trialled on an 11-mile stretch of the M42 in the West Midlands in 2006.

On this system drivers are informed that they can use the hard shoulder by the overhead gantry signs – when they display a red ‘X’ above the hard shoulder it is for emergency use only, when the X changes to a speed limit it’s available for use. Anyone breaking down in such periods has to try to get to a ‘refuge’ – in the first M42 trial these were built at 500-metre intervals, but once the schemes expanded to other motorways the distance between refuges was extended to – in some places – more than 2.5 miles.

From the Dynamic Hard Shoulder concept was soon developed the full-blown smart motorway, known today as All-Lane Running. On these all of the lanes, including the former hard shoulder, are routinely live, but they can all be closed via the overhead gantry if a vehicle suffers an issue and cannot make it to a refuge area.

Such lane closures are intended to be activated by technology that spots if a vehicle has suffered an issue and stopped in a running lane. The initial version of this technology, known as Stopped Vehicle Detection (SVD), was based on radar sensors. However, early smart motorways were not fitted with it, so stranded motorists relying on either being able to contact the motorway control centre or staff in the centre spotting them on the traffic-flow cameras and closing the lane that was blocked.

Issues reported

The amount of the UK motorway network made smart increased rapidly. By 2021, it totalled close to 500 miles with plans to extend this to 800 miles by 2025. And with this expansion grew a fear that such motorways are much more dangerous than traditional versions, following some fatal accidents highlighted in the national media and loudly-expressed concern from motoring bodies.

National Highways, which runs the motorway network, has mounted many a campaign to convince motorists that smart motorways are safe, educating drivers on the correct way to use them. It also claims that, since motorways were turned smart, accidents have been cut by more than half and journey times improved by around a quarter.

In 2020, however, a BBC Panorama programme claimed that 38 people had been killed on smart motorways in the previous five years but perhaps a more telling statistic was the number of near-misses – a Freedom of Information request to the then Highways England, since replaced by National Highways, revealed that on one stretch of the M25 outside London the number of near-misses had increased by 20 times since the hard shoulder was removed.

In the same year the then-chairman of the Police Federation, John Apter, told a conference that smart motorways were “death traps”, and claimed that the design and stopped car detection technology highlighted in the original M42 trial had not been replicated on schemes built elsewhere. “We’ve been misled, it’s inherently dangerous and putting lives at risk,” he said.

Meanwhile an All-Party Parliamentary Group of MPs condemned the continued introduction of smart motorways across the country, arguing that several did not have safety measures, basically the SVD, that “should have been in place before the rollout of these roads commenced”.

The Group argued that the safety of motorists and recovery crews was being put at risk due to the inadequacies of the system, stating that it took Highways England on average 17 minutes to detect a stranded car on a smart motorway and close its lane to other traffic. In 2022, a coroner ruled that Highways England needed to improve smart motorway safety after hearing about an accident on the M1 in 2018, in which a woman was killed when her car was hit 17 minutes after she had broken down in a live lane and been avoided by 153 other vehicles. 

The calls culminated in a government announcement in April 2021 that no new smart motorways would be built unless the SVD technology was installed, transport secretary Grant Schapps also promising that National Highways would complete the installation of the radar-based SVD on all operating all-lane running motorways by September 2022. Other measures would include increasing the number of refuge areas and painting them bright orange so they could be more easily spotted.

The issue also became a political football, with both Liz Truss and Rishi Sunak pledging action on smart motorways as part of their campaigns for the Conservative Party leadership, Sunak claiming in August 2022 that he would ban new smart motorways from being built and describing them as unsafe. In March 2023, as prime minister, he said that the rollout of smart motorways not already in construction had been paused “while we consider the data and next steps.”

Technology issues

Recent revelations have revealed, however, that the SVD technology being present does not necessarily make a smart motorway any safer to use. In January 2023, National Highways admitted to Highways magazine that no SVD system had been declared to be working properly on any section of all-lane running motorway, including on roads the government had pledged not to open without the technology.

Highways was told that none of the retrofit and new ALR schemes were meeting all of the core performance requirements, the NH spokesman adding that this was hoped to be achieved by June of this year.

It was also revealed that the government’s phrase “complete the installation” of SVD had been changed to describe the systems as “in place”, a definition which was still considered acceptable even if the technology was not working satisfactorily.

Highways also discovered that a more recent video version of the technology, that works with the closed-ciruit cameras that monitor stretches of motorway, had been shelved by National Highways, despite trials showing that it was much more efficient at detecting stranded vehicles than the radar-based system.

The radar SVD was claimed to be the “most effective solution” despite it only capturing 65% of incidents, well below National Highways’ own benchmark of 80%. A National Highways chief engineer even told a coroner in 2019 that the radar SVD was only capable of detecting stopped vehicles in low traffic-flow conditions, but other technologies were being explored to detect incidents in high traffic flows.

Drivers ignoring the signs

So technology has caused major issues for smart motorways, but another has been the actions of drivers themselves. The existence of lanes that are sometimes open and at other times not have encouraged some drivers to use them even when designated for emergency-use only with red ‘X’ symbols showing on the overhead gantries.

This had led to major campaigns to educate drivers not to ignore the ‘Red X’, alongside increasing enforcement (using the overhead cameras) and penalties for those that do ignore these signs. These penalties now start at a £100 fine and three points on your driver’s licence, but can increase up to a court appearance.

One of the concerns drivers have voiced over the variable speed limits on the overhead gantries is what happens if the displayed limit suddenly drops by 10mph or more as one approaches the gantry, making it impossible to adhere to the new speed without slamming on the brakes and risking an accident. National Highways insists that there is a slight lag between changes in maximum speed and the speed cameras recording cars travelling above the new speed, so drivers should have time to slow down safely, rather than suddenly, without risking getting a speeding ticket.

So what should you do if you break down on a smart motorway? Obviously, if you are able to, you should head for an emergency refuge – these are much wider than hard shoulder and fitted with phones to contact emergency services. If you are unable to reach a refuge but you are in the nearside lane, try to pull as far off onto the verge as possible, so long as it is safe to do so, then exit the car and get behind the barrier.

If you are forced to stop in anything but the nearside lane, stay in the car, with your seat belt on and dial 999. Motorway authorities will then close the lane using the red X symbols and get assistance to you. Remaining in the protective cell of the car is much safer than trying to cross a live motorway to get to the verge.

In all cases, make sure your car is drawing as much attention as possible to itself by having its hazard flashers on.

Smart motorways – use or avoid?

Taking all of the above into consideration, should drivers be steering clear of smart motorways as a safety risk?

It’s getting harder to avoid them, frankly. While only around 10% of the motorway network has been converted to date, that’s already close to 400 miles of motorway being ‘smart’ in some form – including large sections of some of the busiest motorways in the UK. It’s likely that there will be more to come, despite the various difficulties over the years.

If you’re confident that your car is properly maintained and unlikely to break down suddenly, then there is not a markedly greater risk in using smart motorways. Figures still show that driving on motorways is safer than driving on A-roads.

It’s notable that among those insisting they will never use smart motorways are the owners of classic cars. These, of course, are rather more likely to have a sudden, unexpected issue than are today’s modern cars.

Of course, the other issue with smart motorways isn’t just whether your own car breaks down, but what happens if another car breaks down in the lane ahead of you and the warning systems fail to activate to give you notice of a stranded car up ahead.

Ultimately, smart motorways are a flawed idea that will probably never work as originally intended and the implementation of them has been terrible, with political expediency taking priority over safety. Unfortunately that still leaves 400 miles of sub-par motorway systems that have been foisted on the British public with no satisfactory resolution in sight.

If the technology ever improves to be able to help manage the closing and opening of lanes immediately whenever problems occur and are then cleared, they could still eventually be a good idea. But don’t hold your breath. It’s tough to find anyone – other than National Highways – who thinks smart motorways have been a good idea for the UK.

Unfortunately, we don’t really have a choice. Trying to avoid using smart motorways can add significant distance and time to your journey, which for most drivers isn’t ideal. All we can suggest is to be careful, and pay close attention to what’s actually going on up ahead rather than just relying on the overhead signs.

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Andrew Charman
Andrew Charman
Andrew is a road test editor for The Car Expert. He is a member of the Guild of Motoring Writers, and has been testing and writing about new cars for more than 20 years. Today he is well known to senior personnel at the major car manufacturers and attends many new model launches each year.
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