|Length:||2 miles (3.2 km)|
|Met (1961):||A48, A4119, A470, A469|
|Now part of:||A48|
|Route outline (key)|
The A4056 was the original number given to what is now the A48 Western Avenue in Cardiff. This section of the Cardiff 'inner bypass' vastly predates the 1970s Eastern Avenue which was part of a larger, mostly abandoned, road plan for the city. Despite being of a lesser build quality, it still manages to be a four lane single carriageway with a 40 mph speed limit and Clearway restriction throughout. It would have been superseded by the unbuilt Llantrisant Radial.
In 1922, the A4056 started on the A48 Cowbridge Road in Ely and headed northeast for less than a mile to Llandaff and the A4054 (now A4119). The crossing of the River Taff and the extension to the A470 dates to the 1930s.