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
M32 motorway running lane for its final to a signal controlled junction. The hard shoulder and the remaining width of carriageway were rebuilt as two narrowed running lanes for general traffic, and the speed limit was reduced to . In 2009, the council announced that a park and ride facility would be developed next to the M32 to help alleviate congestion in the city centre. The project was expected to create 1,500 parking spaces and cost £191 million. In 2015, construction began on a bus-only junction between junctions 1 and 2, on land partly allocated to the Stapleton Allotments and near the