This is another of those half do the job then change your mind schemes, such as the southern end of the M53 in Cheshire.
The now A682 through Rawtenstall and Burnley was originally the A56 all the way from Bury to Colne and beyond in each direction.
During the 1960s it was intended to replace the entire then A56 between Bury and Brierfield, north of Burnley, by a new dual-carriageway route. The Edenfield by-pass was the first section to be built, which terminated temporary in the large roundabout just west of Rawtenstall town centre. The next stage, Bury to Ramsbottom, evolved into what is now the M66.
From Rawtenstall it was intended to by-pass Crawshaw Booth and then follow a new line to the junction of the Burnley by-pass (A646) and the then A56. A new route from there, passing to the east of Burnley town centre, to rejoin the original A56 south of Brierfield was planned to replace the steep hill down into Burnley from the A646 by-pass.
However, with the coming of the M65 and later the A680 bypass of Accrington, the plans for a replacement A56 north of Rawtenstall were abandonned, a by-pass of Haslingden, from the end of the local spur from the A56 to the start of the Accrington by-pass, filled the gap in the through route. Unfortunately that resulted in the planned through route into Rawtenstall becoming a local spur and a local spur to Haslingden becoming the through route, with their junction being laid out back to front!