The first of 11 night-time closures of the M1 Princes Motorway will take place tomorrow night in preparation for roadworks at the Picton Road intersection.
The southbound lanes of the M1 from the intersection to Bulli Tops will be closed from 8pm to 5am every night from January 19 to 23.
Then, from January 28 to February 4, the northbound lanes will be closed.
During the closures light vehicles are advised to use Bulli Pass, while heavy vehicles can use Picton Road.
The closures are to allow Roads and Maritime Services workers to reconfigure concrete barriers around the worksite to separate it from traffic.
The $5.5million project is aimed at improving safety for vehicles turning left from Picton Road onto the M1 by replacing the T-intersection with a new 700-metre northbound acceleration lane. At present, heavy vehicles must stop before turning left and then turn onto a road with traffic travelling at 100km/h.
From January 28 until the completion of work – which is expected to take eight months – the left-turn lane onto the M1 will be closed. For that period separate detours will be in operation for heavy and light vehicles.
The heavy vehicle detour is 20.4kilometres along the Hume Highway and Appin Road, adding an extra 25 minutes to a trip. The detour for light vehicles will add just three minutes.