There's a proposal to duplicate the great western highway, with some options for Blackheath area including bridging over Berghofers Pass, Porters Pass and Centenial Pass
news report is here https://www.bluemountainsgazette.com.au ... idge-line/
draft proposal is here https://www.rms.nsw.gov.au/projects/gre ... index.html which includes this in FAQ:
What impact will you have on bushwalking routes?
Where possible, we will avoid impacting bushwalking
routes as we are sensitive to the community’s high regard
for these environmental assets. However, a possible option
for Blackheath would likely impact bushwalking trails to
Fort Rock, Centennial Glen Creek, and Porters Pass Track.
The reserved corridor between Mount Victoria and
Lithgow would likely impact Berghofers Pass.
The program team will consult with stakeholders
such as bush walking groups, local councils, and
others to mitigate impacts during the development
of these options. Further investigations need to be
done to assess the impacts on these trails