I think the transport provider is not up to date. The TasPAWS website announced this last May. They refer to the Sustainable Timbers website
https://sttas.com.au/road-track-closuresTo save you the trouble, here is the text from the site
West Picton Road
In the interest of public safety, West Picton Road is closed (just prior to Riveaux Creek) to all vehicular traffic due to the deterioration of several structures along the road.
The Eastern Arthur Range Traverse (Farmhouse Creek Track) and the Mt Picton Track will remain open to bushwalkers with the development of a vehicle turn around and car parking bay at the junction of the West Picton Road closure location (just prior to Riveaux Creek) provided by Tasmania Parks and Wildlife Service and Sustainable Timber Tasmania.
The Eastern Arthur Range Traverse (The Farmhouse Creek Track) will require (approximately) an extra 7.4km (one way) walk along West Picton Road from its closure.
The Mt Picton Track will require (approximately) an extra 7km (return) walk along West Picton Road and then West Picton Road Spur 1-2 from its closure.