And two schemes currently in construction, M56 J6-8 and M6 J21a-26, will be completed. The below article, by Peter Shakespeare, was written before the news broke, and was published in the April 2023 issue of Transport Engineer.
Fourteen months ago, following a Transport Select Committee (TSC) report into smart motorways, published in November 2021, the government paused the rollout of all-lane running motorway schemes until five years’ worth of safety data is available. This move was applauded by many, including the motoring organisation the RAC.
In evidence presented to the TSC by the RAC, it said that a clear majority of drivers, some 62%, are in favour of scrapping all-lane running motorways and reinstating the hard shoulder. Following the government’s announcement, RAC’s head of roads policy, Nicholas Lyes, said: “This watershed decision is an unqualified victory for drivers, many of whom have deeply-held concerns over the safety of motorways where the hard shoulder is permanently removed.”
There are three types of ‘smart motorway’ in the UK, and were defined by TSC (see table, right). Controlled motorways retain the conventional motorway configuration, including retaining the hard shoulder, but have additional technology such as variable and mandatory speed limits to control the speed of traffic and overhead electronic signs to display messages to drivers. Dynamic hard shoulder (DHS) running motorways apply controlled motorway technology, but temporarily increase capacity by utilising the hard shoulder as a running lane at peak times. DHS motorways also have emergency areas providing a safe place to stop in an emergency, set away from the carriageway. All lane running (ALR) motorways apply controlled motorway technology as described above but permanently convert the hard shoulder as a running lane, increasing capacity. ALR motorways also feature emergency areas and stopped vehicle detection technology.
In June 2022, the Royal Society for the Prevention of Accidents (RoSPA) published its own interpretation of the safety of smart motorways based on evidence gathered from the National Highways’ 2022 Smart Motorways Stocktake, second year progress report 2022 (www.is.gd/xadeja) and DfT’s Smart Motorway Safety, Evidence Stocktake and Action Plan (www.is.gd/xededu).
RoSPA says that each smart motorway must be at least as safe as the traditional motorway it replaces. It asserts that in terms of fatality rates, smart motorways continue to be the safest roads in the country. Between 2016-2020, conventional motorways had a five-year average of 0.15 fatal casualty rate per hundred million vehicle miles travelled, while ALR, DHS and controlled motorways had a fatal casualty rate per HMVM of 0.12, 0.09 and 0.07 respectively. All of the above motorways performed better than A-roads, which had a five-year average fatal casualty rate of 0.41 for the same period.
DIFFERENT RISKS
RoSPA concludes that while smart motorways had a lower fatality rate than conventional motorways, for the five-year period, government data suggests that on smart motorways, some risks are reduced, while others increase. It says: “On ALR there is an expected reduction in the risk of drivers speeding or tailgating, but an increased expected risk of collisions involving vehicles stopped in a live lane. Most collisions occur between moving vehicles, while stopped vehicle collision rates range from 2.36% for controlled motorways, 2.99% for conventional motorways, to 5.26% for ALR motorways.”
It continues: “While the risk of a live lane collision between a stopped and moving vehicle is greater on ALR and DHS motorways, the risk of collision involving only moving vehicles is lower. Before and after data on DHS schemes suggest that personal injury collisions are reduced. Overall, the evidence has demonstrated that while the nature of the risks varied between the motorway types, ALR was expected to reduce the overall level of risk by 20% and be as safe as, or safer than, conventional motorways. Even though fatal casualty rates on the ALR network are lower, injury rates are higher. DHS motorways have a lower fatal casualty rate and a slightly higher rate of slight and serious casualties.”
One particular area that concerns the smart motorway safety lobby are collisions involving vehicles stopped in a live lane. On this point, RoSPA reports: “Collisions tend to be infrequent, with an average of 19 collisions per year across nine of the 12 ALR schemes, being far lower than the 9,206 live lane breakdowns per year across all ALR schemes.”
In its 2021 report, the TSC required retrofitting additional emergency refuge areas to existing all-lane running motorways to make them a maximum of 1.5km apart (2.5km as built), decreasing to every 1km where physically possible. It also commissioned the Office of Rail and Road (ORR) to conduct an independent evaluation of the effectiveness and operation of stopped vehicle detection (SVD) technology (including maintenance and monitoring). It also inserted the emergency corridor manoeuvre into the Highway Code to help emergency services and traffic patrol officers to access incidents when traffic is congested. Following the TSC’s recommendations, DfT’s action plan also included an action for National Highways to retrofit radar-based SVD technology across all ALR motorways.
In December 2022, ORR published its first annual assessment of safety performance on the strategic road network and progress update on TSC’s smart motorways recommendations. It reported that National Highways met its action to have this technology in place on every existing ALR motorway, but the technology’s performance is not expected to be on par until July.
Although the ORR report said that good progress had been made on updates, it is too early to make an overall assessment whether the frequency and duration of live lane stops have reduced and whether drivers’ perception of safety has improved.
In its 2022 second year progress report, National Highways said that not until late 2023 will data be available on recently implemented technologies.
DfT said that during the smart motorway implementation pause, it had committed £900 million for safety improvements across the network, including more emergency areas.
ANALYSIS
There is no doubt that the concept of removing the hard shoulder as a place of refuge on motorways is counter-intuitive in the eyes of most drivers. But the accident statistics – despite their relative infancy and skewing by the COVID-19 pandemic – do paint an optimistic picture; and if the action plans to address safety concerns can be proved to be effective, it is hard to make a case to scrap these sections of the road network or ban further development, despite the underlying political pressures.
Ultimately drivers cause accidents, not roads, and Thames Valley Police’s recent statement that over 3,000 offences (ignoring lane and speed restrictions) have been committed on the M4 section of smart motorway since its completion speaks volumes. Driver education and enforcement will have the biggest effect on smart motorway safety, so only time will tell if the messages get through. -Peter Shakespeare