The eastern end of Heathcote Road will be closed again this weekend, starting at 8pm tonight (Friday June 24), for work on the new bridge over the Woronora River.
The road between New Illawarra Road and Princes Highway will be closed until 5am on Monday June 27 while rock is excavated at the western approach to the bridge.
Transport for NSW says work will be carried out 24 hours per day during the closure to minimise the number of closures needed overall.
A detour that is suitable for freight and B-double trucks up to 26 metres long will be in place via Princes Highway at Kirrawee and the Bangor Bypass.
"Motorists are asked to plan ahead and allow additional travel time, and it is recommended alternative routes be used where possible," a spokesman said.
"Motorists are also advised to expect delays at the existing traffic congestion points at Linden Street during the weekend peak periods.
"Transport for NSW will be monitoring queue lengths and temporary local road traffic changes will be in place between 9am and 4pm at Linden Street and Leonay Street in Sutherland to reduce congestion during the peak period.
"The detour may add up to 30 minutes to journeys, so motorists are asked to plan ahead and also allow additional travel time for possible traffic congestion."
A further six weekend closures will take place between July and September.