Traffic control measures and electronic signs are in place at Khancoban, Jindabyne and Tumbarumba to direct motorists following the closure of the Alpine Way.
The Alpine Way between two kilometres west of Thredbo and Khancoban is closed after a rock fall caused debris, including rock and soil to fall across the road. It is expected to stay that way until September 20.
Roads and Maritime closed a 70 kilometre stretch of Alpine Way on Thursday. The closure will remain in place until the debris is cleared.
The rock fall has occurred from the top of the slope at the same location where emergency work was carried out last month.
Roads and Maritime inspected the road yesterday. Specialist equipment was sent to the site and clean-up work was scheduled to start Friday.
Motorists intending to travel on the Alpine Way between Khancoban and Thredbo near the National Parks and Wildlife Gate at Thredbo will be redirected to travel via the Snowy Mountains Highway via Tumut, Tumbarumba and on to Khancoban.
The detour is expected to add about three and a half hours to the journey and motorists are advised to delay non-essential travel.
Motorists are advised the Alpine Way between Jindabyne and Thredbo Village remains open. Access to Khancoban town has been maintained from Tumbarumba and Corryong.
Another alternative travel route between Khancoban and Thredbo is via Elliott Way from Tooma and Mount Selwyn.
Planning for new fencing which started after the existing fence was damaged last month will now incorporate the latest rock fall in proposed improvements.
Motorists are advised to drive with caution, obey all signs and the direction of traffic controllers and allow extra travel time.