The original safety assessment of All Lane Running (ALR) included the safety of a vehicle stopping in a running lane during peak and off-peak periods. It also identified a range of measures, such as the provision of traffic management technology and emergency areas, designed to ensure that overall ALR safety levels would be at least as safe as those of a traditional motorway with a hard shoulder.
The smart motorway schemes between junctions 5-7 and 23-27 of the M25 were the first to be designed to the ALR standard, and were completed in 2014. The performance of both schemes was monitored, and reports were published after one, two and three years of operation, which included an assessment of safety and performance data.
M25 three-year evaluation reports:
The reviews show that the All Lane Running sections are performing in line with expectations, successfully increasing capacity and improving journeys for motorists. These reviews also found that the M25 schemes delivered a 27% safety improvement overall.