The reports on the all-lane running sections on the M25 J5 to 6 and J23 to 27 have been published by Highways England based on a 12-month evaluation.

For the J23 to J27 section, Highways England found that the scheme has experienced traffic growth of approximately 10% between the Before and After periods, which is far higher than motorway, national and regional growth over the same period.

Average journey times have reduced by 5% overall in the clockwise direction and 9% anticlockwise.

For the J5-6 section, the report found that traffic flows have increased by 13% clockwise and 3% anticlockwise. The scheme has experienced traffic growth of approximately 2% between J6 and J7, which was not previously at capacity and did not have any lanes added; this is in line with regional growth trends.

Average journey times have reduced by 3% overall in the clockwise direction and 2% anticlockwise.

For both sections, the research identified a “small (but not statistically significant) reduction in collision rate, over and above the national background of improved safety”, indicating that safety has not worsened as a result of the scheme.

However, the report also looked at Red X compliance and found that across all events analysed, an average of 7% of vehicles did not comply with the Red X.

It added that driver awareness of the scheme and the term ‘Smart Motorways’ is split with only 42% of all users being aware of the changes. Significantly, over a quarter of drivers using the scheme are unaware of the change to all-lane running.

However, whilst awareness of smart motorways is low, understanding of the motorway signage associated with the scheme was high, particularly regarding the use of a Red X and mandatory speed limits.

Most respondents were aware that using Emergency Refuge Areas (ERAs) for non-emergency matters such as map reading, making phone calls or getting something out of the boot was inappropriate. However, 21% of non-local road users thought that it would be permissible to use an ERA to attend to a child.

Highways England also found a reluctance amongst drivers to use the inside lane (old hard shoulder). Some of the reasons for this behaviour revealed an uncertainty or lack of understanding about all-lane running with drivers commenting that the inside lane is more dangerous or can be used only in an emergency.

RAC chief engineer David Bizley said: “The results of these initial reports suggest that motorists are still getting to grips with how to make proper use of motorways with all-lane running (ALR). This is consistent with our own research on this subject.

“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.”