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 Bay Gateway) has completely re-modelled this junction with a wide additional bridge over the River Lune and other works repositioning slip roads with new acceleration lanes to modern standards. The route was originally intended to replace the old A6, which it does along the northern section starting with the Preston Bypass. However, a much closer approximation to the overall actual route of the M6 (heading north from its southern terminus) is provided by following the A45, A34, A50, A49, then the A6. South of Preston, the A6 route is instead supplemented by the M61 as far as Manchester, with the