M20 Rosbrien Interchange (Limerick) to Patrickswell The route starts at junction 1 at the Rosbrien interchange (south of Limerick city) where it connects to the
M7 and the
N18 which together form the Limerick Southern Ring Road. The route continues from this interchange as
motorway. This route was redesignated as motorway in August 2009. The route bypasses
Dooradoyle and
Raheen, through which the old N20 route used to run until the early 2000s. Interchanges and link roads connect to these locations. Two further interchanges are located on the motorway, at either end of Patrickswell. At the latter, the N20 route leaves the main road (which continues as the
N21 to
Tralee), so one must diverge from the motorway to stay on the N20. The former route of the N20 before the M20 opened is now classified as the
R526.
N20 Patrickswell to Cork City A wide two lane road brings traffic along the Croom bypass (prior to the opening of this bypass at a cost of €20 million on 12 July 2001, the route went through the town). Past this new section of road, narrow two-lane road commences, ending at Charleville. The route passes through the town, running along Main Street. The road between Charleville and Buttevant is of similar design. At Mallow a relatively high specification road is encountered, with an older bypass of the town (early 1990s) passing up the hill from it as
dual carriageway. A viaduct brings the road across the
Blackwater River and Valley. The rest of the route to Cork is two lanes wide, with a section of
2+1 road (a pilot installation) south of Mallow. The route becomes dual carriageway on the approach to Cork. Junctions on this dual carriageway section are not numbered. New relief roads in Cork bring the route into the city centre while avoiding the winding streets through which the route ran until around 2000. The route terminates at the city center with two lanes going in each direction. ==M20 motorway==