Preston By-pass Preston By-pass The Preston Bypass was Britain’s first motorway. It was designed and engineered by Lancashire County Council surveyor James Drake as part of a larger initiative to create a north-south motorway network that would later form part of the M6 motorway. The bypass was opened on 5 December 1958 by the Prime Minister, Harold Macmillan. Nearly £3 million was spent in its construction. The original -mile () motorway ran around the east side of Preston between Bamber Bridge (now the M6, Junction 29) and Broughton (now the M55, Junction 1) and crosses over the River Ribble at Samlesbury at
M6 motorway 1970, the Lancaster–Penrith link was completed, along with a short section of motorway by-passing the south of Walsall. The most northerly section of the motorway also opened in 1970, running to the designated terminus north of Carlisle. By 1971, the full route was completed between the junction with the M1 motorway at Rugby and the A38 road several miles north-east of Birmingham city centre, including Bromford Viaduct between Castle Bromwich (J5) and Gravelly Hill (J6), which at 3½ miles is the longest viaduct in Great Britain. Junction 6 in Birmingham is widely known as Spaghetti Junction because of its complexity