B21 (Northern Ireland)
|Location Map ( geo)|
|Distance:||5.2 miles (8.4 km)|
|Meets:||A21, B20, B197, A2, A48|
|Old route now:||A48|
|Route outline (key)|
The B21 is a short B-road in north County Down.
The road starts at the northern end of the A21 in Bangor, at the point where Main Street changes from two-way to one-way. The B21 heads north along the remainder of Main Street, meeting the B20 and then bearing right into High Street. This road becomes two-way at the junction with Bingham Street which theoretically takes southbound B21 traffic (although the road is unclassified). Eventually a roundabout is reached with the B197; this classified road does complete the town-centre one-way loop.
A short distance further on, the unclassified Groomsport Road bears off to the left. This point is the original western end of the B21; all that has gone before was the original line of the A2 and became the B21 when that road was diverted onto the southern bypass. The bypass itself is crossed at a roundabout shortly afterwards and then the B21 enters open country.
The road runs across the fields for a couple of miles as the High Bangor Road - presumably an alternative to the longer but flatter A2 along the coast - before reaching Donaghadee. The road ends on the western side of town at a junction on the A48, where that road has to TOTSO. The junction layout is explained by the fact that until the inauguration of the A48 in the mid-1920s the B21 continued ahead into the centre of town to end on the A2.