M25 ‘smart’ motorways are having ‘no adverse effect on safety’


Sections of ‘smart’ motorways on the M25 are easing congestion and reducing journey times, with no adverse effect on safety, according to evaluation carried out by Highways England.

Highways England has published two interim reports evaluating the all-lane running sections on the M25, J5 to 6 and J23 to 27.

For the J23 to J27 section, average journey times have reduced by 5% in the clockwise direction and 9% anticlockwise, while for the J5-6 section, average journey times have reduced by 3% in the clockwise direction and 2% anticlockwise.

These reductions come against a backdrop of increased traffic flow between the ‘before and after’ periods; 10% between J23 and J27 and 13% (clockwise) and 3% (anticlockwise) between J6 and J7.

With regard to safety, in both cases there has been a “small but not statistically significant reduction in collision rate”. This leads Highways England to conclude that “while the reduction is not significant, the results provide an initial indication that safety has not worsened as a result of the scheme”.

Monitoring of ‘Red X compliance’ (indicating a lane should not be used) revealed that an average of 7% of vehicles were non-compliant, a figure which the RAC says gives ”cause for concern”.

The reports also indicate driver awareness of the scheme and the term ‘Smart Motorways’ is split, with only 42% of all users being aware of the changes.

Highways England says that Smart motorways are ‘central to the modernisation of England’s motorways’ and have been designed to reduce congestion, improve journey time reliability and lead to shorter journey times, while at the same time maintaining safety.

Formerly known as managed motorways, smart motorways use a range of  technology to vary speed limits in response to driving conditions. They are divided into three different types: controlled motorway, all-lane running and hard shoulder running.

In December 2015, the Transport Committee launched an inquiry into the impact of all-lane running to inform how future policy  should evolve.

The RAC says the evaluation results “suggest that motorists are still getting to grips with how to make proper use of motorways with all-lanes running (‘ALR’)”.

David Bizley, RAC chief engineer, said: “Non-compliance with red ‘X’s on ALR stretches of motorway is a particular cause for concern. With no permanent hard shoulder, the safety of someone breaking down in lane one is highly dependent on motorists obeying overhead signage indicating the closure of a lane to traffic.

“The misuse of Emergency Refuge Areas (ERAs) is also worrying. With spacing of ERAs further apart than on earlier designs of smart motorway and in the absence of a hard shoulder it is essential that ERAs are used only by those road users that are faced with a genuine emergency.

“It is encouraging that initial evidence suggests the safety performance of ALR to be no worse than a conventional motorway with a hard shoulder and indeed may be slightly better, but by Highways England’s own admission, a further two years data will be needed before there is sufficient evidence to be confident in this conclusion.”

Photo: Highways England via Flickr