The M66 motorway is a motorway bypass for the large town of Bury and several other towns and villages on the route of the A56 to the North of Manchester.
The M66 is fairly short, at just under 9 miles or about 14 km, but has been longer in the past. Until 1998 the M66 continued to what is now junction 19 of the M60, with a further section running from Denton down to Stockport with a gap of about 9 miles in between.
In 1998, the M66 was cut back to the Simister Island interchange, now junction 18 of the M60 and M62, with the southern sections renumbered M60 in advance of the 9-mile gap being completed in 2000.