M55 motorway meet junction 4, where the motorway ends and becomes the A5230. The western part of the M55, and the first few hundred metres of the A5230, occupy the route of the old Blackpool Branch railway line. The first motorway constructed in Great Britain was the M6 Preston Bypass, opened in 1958. This ran from the current M6 junction 29 to the M55 junction 1. It was built as a two-lane route. In 1965 the M6 was extended north from what is the current day junction 32 to meet the Lancaster Bypass, and the M6 junction was rebuilt to its current
M6 motorway (Ireland) and M4, which form the Galway-Dublin route, consist of a grade-separated 2+2 dual carriageway road with a top speed limit of 120 km/h. At approximately 144 km (90 mi), the M6 is the third longest motorway in the state. Near Kinnegad, the M6 motorway diverges from the M4 at a restricted access junction. From here it proceeds westward, passing through counties Westmeath, Offaly, Roscommon and Galway before terminating just east of Galway City near Doughiska. The present-day M6 was constructed in five stages between 2005 and late 2009. Some of the sections which now form part of the M6 were