 After Victoria converted to alphanumeric route markers the Victorian section was signed as B23 . In 2013 the NSW / ACT conversion to alphanumeric routes occurred and the remainder of the highway ( south of Hindmarsh Drive in the ACT ) was then also signed as B23 . The route duplex along the Monaro Highway remains intact with <unk> used in addition to B23 between Steeple Flat and Cooma , to link the two sections of the Snowy Mountains Highway . North of Hindmarsh Drive , the highway no longer carries a route marker . 
