Overall the analysis of 12 months worth of data completed under the Active Traffic Management (ATM) monitoring and evaluation project has confirmed, and are consisten with, the 6 month results. 4 lane variable mandatory speed limits (4L-VMSL) offers a significant improvement in traffic conditions on the M42-ATM section. This report supersedes the 6 month report as it provides an evaluation over a longer time period. It also demonstrates the consistency of the impact of 4L-VMSL between the winter and summer seasons and increases confidence in the results. The introduction of 4L-VMSL has successfully reduce congestion, improved journey time reliability and increases the available capacity of the M42-ATM section.