Mallwyd

Mallwyd is an important junction in Mid Wales. Historically it was where where traffic heading west from Shrewsbury to the Merionethshire coast split between Dolgellau and Machynlleth.

History

Road numbers 1922-1935

Originally, this was a crossroads. In 1922 the roads to the south and north east became the A491 route between Shrewsbury and Machynlleth, while the road to the north west became the A4084 route linking the A491 to Dolgellau. In 1935 the route numbers entirely changed: the A458 was extended from Shrewsbury to Dolgellau and the A4084 switched to run south of the junction towards Machynlleth.

Road numbers post 1935, showing the roads as trunk roads

In 1946, the A458 was trunked. In the mid-50s, the A4084 was also trunked. The A470 renumbering took the A4084 number from the junction, after over 50 years, taking over both routes that have held that number.

Routes

Route	To	Notes
A458	Y Trallwng / Welshpool
A470	Dolgellau, Dinas Mawddwy
A470	Llangurig, Machynlleth, Y Drenewydd / Newtown (A489)
		7'6" width limit 350yds ahead / ymhen 350 llath
A458	Dolgellau, Dinas Mawddwy	post-1935, now A470
A491	Y Trallwng / Welshpool	post-1935, now A458
A491	Machynlleth	pre-1935, now A470
A4084	Dolgellau, Dinas Mawddwy	pre-1935, now A470
A4084	Machynlleth, Llangurig, Y Drenewydd / Newtown (A489)	post-1935, now A470