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) initially opened as dual-carriageway and previously formed part of the N6, while other sections were opened as motorway. In chronological order, the various sections opened as follows (status on opening in brackets): From 24 September 2008, motorway regulations were applied from Kinnegad to the eastern end of the Athlone bypass. The Kinnegad-Athlone scheme was signed as a motorway (and numbered "M6"). Its road markings were already appropriate to a motorway prior to the change in designation coming into effect; however, motorway regulations were not in force and the speed limit was 100 km/h until 24 September of that year. Construction