 Passenger train services over the bridge declined significantly after the Ruabon to Barmouth line via Llangollen and Dolgellau was closed in 1965 , causing all traffic to take the longer and slower route from Shrewsbury via Machynlleth and Dovey Junction . The old trackbed from Morfa Mawddach railway station to Dolgellau now forms the Mawddach Trail , a walk and cycle trail . 
