 Construction of the 600 m ( 2 @,@ 000 ft ) Taff Viaduct ( Welsh : Traphont <unk> ) includes a dual @-@ carriageway roadway plus a foot and cycle path . South Glamorgan County Council was the local authority in charge of the project at the time and construction of the viaduct began in March , 1991 . The Taff Viaduct crosses the River Taff at Cardiff Bay . 
