|Location Map ( geo)|
|Via:||Northfield, Weoley Castle|
|Distance:||5.1 miles (8.2 km)|
|Meets:||A441, A38, A4123|
|Route outline (key)|
The B4121 is an L-shaped road in the south west of Birmingham.
The route starts just north of King's Norton in Cotteridge at a roundabout junction with the A441. It initially runs westwards as the single-carriageway Middleton Hall Road before, approximately one mile later, becoming the Bunbury Road as the road passes into the suburb of Northfield. It continues for another mile before, at a TOTSO, turning right (north) into Church Road, although traffic for the A38 southbound continues along the unclassified Great Stone Road.
At the top of Church Road the road meets the Bristol Road South (the old route of the A38) at traffic lights before meeting the present A38 Northfield by-pass at traffic lights. From Northfield northwards the road becomes a different affair, being dual-carriageway (it is also a far newer road, not existing in full until the 1970s). It continues as Bell Hill, Shenley Lane and Barnes Hill passing through the valley of the Merritt Brook and past Shenley Academy before meeting Weoley Castle Road at a traffic island at the summit of Barnes Hill approximately 1 mile north of Northfield. From here it continues towards California, after which it becomes West Boulevard passing through the eastern edge of Woodgate Valley Country Park and into Quinton. It now passes over two further roundabouts before meeting Tennal Lane at a roundabout and continuing to the left before ending on the A4123 Wolverhampton Road South at the next island.
The number B4121 was originally allocated only to the section between Cotteridge and Northfield. The route north of Northfield was unclassified, though there were clearly grand plans for it, given the construction standards. West Boulevard was also constructed to a much higher standard than would be expected for a merely local road. The dots were joined in the mid-1980s when the West Boulevard extension was constructed across the Woodgate Valley, joining up roundabouts at West Boulevard/Quinton Road West and Barnes Hill/Stonehouse Lane. The classification B4121 was then extended to include the completed road, allowing it to function as a route relieving Selly Oak and Harborne of through traffic between south Birmingham and the Black Country.