 The map to the right visually represents the operational and under construction elements of the UK's smart motorway system as of June 2017.In 2007 it was estimated that ATM could be introduced within two years at a cost of around £5-15 million per mile as opposed to 10 years and £79 million per mile for widening.The M42 scheme was initially run as an experiment and a Highways Agency report into the first six months of the scheme showed a reduction in variability journey times of up to 27%.