The Highways Agency claims that scrapping motorway hard shoulders in the name of increased capacity has had no major impact on safety despite reservations from politicians and the police. Jon Masters examines the safety case.
Using hard shoulders as live traffic lanes during busy times is becoming common practice across the UK. Early schemes include the M42 around Birmingham, the M1, M4, M5 and M25.
So far they have all had a common feature “dynamic” hard shoulder running switched on only at peak periods.
Now the Highways Agency is moving beyond using the hard shoulder at peak times toward permanent all lane running (ALR) with hard shoulders removed to widen motorways to four lanes. The first sections of these managed motorway are being built on the M25 between junctions five and seven and from junctions 23 to 27. More will follow on the M62, M1, M4, M5 and M60.
There is concern that squeezing extra capacity from motorways in this way will increase risks faced by motorists. They fear that removing the hard shoulder increases the risk of accidents caused by broken down vehicles stopping in live traffic lanes.
Sheffield MP Meg Munn and a delegation including other politicians local to the M1 corridor and South Yorkshire Police met with transport minister Stephen Hammond this month to voice their concerns. The Agency’s programme includes an ALR scheme between junctions 32 and 35a of the M1 in South Yorkshire.
“We felt we hadn’t received satisfactory responses to our concerns, particularly on the safety issue,” Munn says.
“Police are concerned about how ALR will impact their operations and local authorities are worried about more motorway closures [as a result of accidents] “
Meg Munn MP
“Police are concerned about how ALR will impact their operations and local authorities are worried about more motorway closures [as a result of accidents] putting more pressure on local roads. I do not see the need for 24 hour hard shoulder running.
“I appreciate the need for it at peak times, but in off-peak periods it will be more dangerous.”
The Agency claims that overall the calculated accident risks are lower than those of the baseline of a conventional three lane motorway. It predicts that ALR will reduce safety risks by 10% to 15% over its baseline.
“We can show the engineering analysis behind ALR, but it remains very difficult to change people’s emotional feelings about the principle,” says the Agency’s ALR programme manager Andrew Page-Dove.
“Arguments against ALR have been entirely anecdotal so far. They would be more credible if they were based on evidence that we could assess.”
“ALR is not something we thought up as a good idea and are now seeking information to prove. We used a lot of evidence to come to the decision.”
The Agency’s analysis has included assessment of how around 2,000 people of various age groups have reacted when using an ALR simulator at transport research body TRL’s headquarters in Crowthorne. The Agency is now using the simulator to demonstrate the principles of ALR to stakeholders.
Page-Dove says that a publicity campaign is being planned to tell drivers what to do if their vehicle breaks down in live carriageway (see box).
The Agency’s analysis shows that ALR will increase the risk of breakdowns in live carriageway by over 200%. But this does not mean there will be twice as many accidents, it says.
In a recorded address given at TRL’s Crowthorne headquarters earlier this month, Hammond said ALR is a “quick, safe and viable” solution for relieving congestion.
“Our motorways are already among the safest in the world and I am confident they will get safer. I understandconcerns over breakdowns in live lanes, but I am also sure the emergency services and the Highways Agency will establish safe procedures,” he said.
But it is worth noting that safety standards used on the active traffic management (ATM) schemes, which pre-date managed motorways have been scaled back.
The first ATM scheme, was a pilot on the M42 in the West Midlands in 2005. It features overhead gantries and emergency refuge areas spaced 500m apart. The gantries carry variable message signs used to vary mandatory speed limits and set lane closures as needed. Traffic officers based at the Agency’s West Midlands control centre still run through an exhaustive procedure of checking that the hard shoulder is clear before opening it to traffic twice daily.
“We are still making motorways safer and it would take far longer to bring the same benefits with conventional motorway widening”
Andrew Page-Dove, Highways Agency
According to Page-Dove, the predicted benefit was a 10% to 35% reduction in accident figures on the M42.
“We got a lot more,” he says.
The actual results from the M42 show accident risks were more than halved, in comparison to the three lane motorway baseline, effectively rubber-stamping the approach for adding capacity at peak times elsewhere.
But for the next managed motorway schemes on the M6 and M1, fewer gantries and refuge areas were built, at distances of at least 800m apart.
Several years and more experience later, the Agency’s standard design for ALR now positions variable message signs and refuges 2.5km apart.
“This is generally the same as all-purpose trunk roads, but a managed motorway has more control. We have some good comparators for assessing safety,” says Page-Dove.
The apparent lowering of safety provision on managed motorways is “not about saving money”, Page-Dove says.
“It is about allowing more to be reinvested in the network over a shorter timeframe.
“It is important to remember that we are still making motorways safer and it would take far longer to bring the same benefits with conventional motorway widening.”
What to do if your car breaks down
The Agency’s advice for motorists that break down and cannot reach an emergency refuge area, is to try to get their vehicle onto the verge if it is safe to do so.
Failing that, the advice is to stop in the outer- or innermost lane, exit the vehicle from the left hand side onto the verge or stay in the vehicle until help arrives. According to Highways Agency traffic officer Stuart Milligan lanes one and two of a motorway will be closed if a vehicle is stranded in either of them. Both outside lanes will be closed to rescue motorists broken down in either of lanes three and four.
The reduction in safety provision has undoubtedly reduced the costs of managed motorways. Figures obtained from the Agency show that the M42 scheme added £8,750 of operating cost per lane kilometre to that motorway annually. Later, slimmed-down versions of managed motorway with dynamic hard shoulder running added £2,500 per lane kilometre. ALR adds £1,250, not including added maintenance costs which the Agency says will be 30% less with ALR.
There is another reason for reining in safety provision on the newer managed motorways. Group manager for safety risk governance Martin Lynch has oversight of all of the Agency’s safety efforts. “When all of the current managed motorway programme is built it will still cover only 5% to 8% of the motorway and trunk road network,” he says. “Spending the same as that spent on ATM (which cost about £10M per km to build) and setting that as the benchmark is just not good value for money.”
So what does get the best safety return for the investment?
“A traffic calming scheme on a single lane trunk road is by far the most cost effective use of the Agency’s money for improving safety. The worst performing single lane roads on the network are six times more dangerous than a conventional motorway,” Lynch says.
Aside from the safety discussions, the Agency describes managed motorways as principally congestion management schemes. But it has to balance this with the needs of its stakeholders, particularly emergency services.
“Discussion on the detail of operation of ALR will continue and rightly so,” an Agency spokesman says. “The aim is to introduce congestion management schemes that are at least as safe as the current situation. Monitoring will continue once ALR is in place. We will mitigate if it is found unsafe.”