The A6119 forms a half-ring around Blackburn. Since the opening of the M65 in 1997 much of its strategic importance has been lost, but it still remains a busy local route. It was constructed in the mid-1920s, opening all together in 1927. It featured dual carriageways at Brownhill in expectation of a never-realised tramway scheme. The rest of the route was dualled between the 1950s and 1990s. This route description starts at the western end, at Shackerley Bar where it branches from the A677.
This section of the ring road was dualled in the 1950s and features ribbon development from the town's overspill estates of Lammack and Beardwood. The first junction with Whinney Lane is an uncontrolled staggered junction on a crest and is a bit dodgy, which was one of the reasons this road was given a 50mph speed limit in the early 1990s when it was still trunk. A pre-Worboys Dual Carriageway Ahead sign still survives on Whinney Lane, giving clues to the age of the road. Beyond here, the westbound carriageway has a service road, but the eastbound has direct frontages. This continues past the first signalised junction with Lammack Road and stops before the next junction at the Knowles Arms, where the B6233 ends. Before the 1990s the road reduced to a 30mph single carriageway here to cross over the Ribble Valley Line before crossing the A666 at the notorious Brownhill Roundabout. The Department of Transport (as was) felt the need to sort this even though by the time it was done the M65 was only two years from opening. The reconstruction works dualled the remaining gap over the railway and replaced the roundabout with a Byzantine signalised crossroads.
The A6119 then enters the original dualled section from 1927 as it climbs past St Gabriel's Church and has a 40mph limit which was extended beyond the Emerald Avenue signals in 1999. A brief rural section follows once the 50mph limit resumes and the road crosses Whalley Old Road at a staggered junction with signal control. From here to the M65 the scenery becomes industrial. The former Mullard (later Phillips) factory was on the right at the Phillips Road junction and the large Whitebirk Industrial Estate is to the left. Prior to 1984 the road again reduced to single carriageway and passed under the East Lancashire Line at the site of the former Blackburn (Whitebirk) Generating Station which was demolished in 1982. The A6119 was redirected east to meet the new motorway at Whitebirk Interchange leaving the old road as a stub.
The ring road officially ends here, and traffic continues along the A678 (along a section with a massive central reservation showing that the M65 was once planned this way) to the Red Lion Roundabout (the old road stub is hidden behind foliage surrounding the roundabout). The A6119 then returns to its original course along Whitebirk Road passing a 1930s overspill estate. It ends, somewhat modestly, at the Intack traffic lights on the A679. The road ahead is the B6130.
The eastern half of the A6119 is sometimes marked as non-primary on modern maps. This is partially reflected by new road signs but the majority of signs still remain green. The section between the A679 and A678 is certainly non-primary, having been downgraded upon completion of the motorway in 1997. It should have, realistically, been renumbered to the B6130 in 1984 when trunk status was removed from the A679 as this section is now purely a local road. The western half of the A6119 is still primary.