The Highways Agency – Britiain's Most Improved Road - Carlisle to Gretna
From the 1960s onwards, the M6 was extended northwards and the route to and from Scotland underwent a gradual conversion to motorway standard. By 1992, the missing 10km section in England running up to the border began to gain notoriety and came to be known as the 'Cumberland Gap'. It took 16 years until the M6 was finally extended northwards.
Of the 2,700 separate road sections studied in the 2013 EuroRAP results, the 10km section between the M6 at Carlisle and just south of the Scottish border at Gretna was the most improved road.