The A489 is a strategic East-West route of national, regional and local importance; it runs from the A483 at Newtown to Machynlleth and is split into two distinctlengths by the A470. The southern section links the A483 at Newtown to the A470 at Caersws. The Northern section links the A470 at Cemmaes Road to the A487 at Machynlleth. Both sections are generally a single carriageway road of varying width and standard.
The Southern section of the A489 Trunk Road is 8.5 Kms (5 miles) in length and links the settlements of Newtown and Caersws. The Northern section of the A489 Trunk Road is 9 Kms (5.5 miles) in length and links the settlements of Cemmaes Road and Machynlleth.