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 motorway Usk bridge M4 motorway Usk bridge The M4 motorway Usk bridge (or St. Julians Bridge) carries the M4 motorway across the River Usk in the city of Newport in the United Kingdom. The bridge is actually two separate bridges for the eastbound and westbound carriageways. When travelling westbound, the bridges lead directly into the twin Brynglas Tunnels. Work commenced on both the bridge and the tunnels on 10 September 1962, two months after work commenced on the George Street Bridge further downstream. The entire Newport bypass section of the M4 (junctions 24 to 28) finally opened in 1967. In 1989 a further