M4 motorway not signed, European route E30 includes most of the M4. The M4 has two sections of smart motorway. The one between junctions 19 (M32) and 20 (M5) north of Bristol has variable speed limits and a part-time hard-shoulder. Completion was in summer 2014. The section between junctions 24 and 29 in Newport has variable speed limits. In 2010 it was announced that a smart motorway would be constructed between junctions 3 and 12, with work starting in Autumn 2018. This will be the longest smart motorway scheme in the United Kingdom, with a length of 51km (32 miles). Work is
M4 relief road M4 relief road The M4 relief road is a proposed motorway south of the city of Newport, South Wales. Originally proposed in 1991, the scheme was dropped by the Welsh Government in 2009 when costs had risen to £1 billion. They were revived in 2011 with indications of support from the Treasury given in April 2013. There was controversial media speculation that it would be the United Kingdom's second full toll-paying motorway. In July 2014, the Welsh Transport Minister, Edwina Hart, stated that the scheme, following the so-called 'black route', would go ahead and could be completed by 2022. A