Just weeks before it was due to start, the two-month closure of Lawrence Hargrave Drive has been pushed back.
Also, dedicated buses will be provided for students cut off from their school due to the closure - but they will have to get up much earlier than usual.
The work on slope stabilisation that would see the road closed near Stanwell Park from June 9 has been put off until June 15.
The change also means the work will finish a week later than planned - now wrapping up on August 9.
The reason for the change is track work taking place on the South Coast line on June 13 and 14.
With buses scheduled to replace trains between Port Kembla and Wollongong, and between Dapto and Central, the road closure at Stanwell Park would cause access problems for those replacement buses in the northern suburbs.
Transport for NSW also stated dedicated school shuttle buses will be available to transport primary school children who attend schools and services on the opposite side of the closure from their homes.
The school shuttle buses will not be permitted to travel through the work site but will use the Bulli Pass-M1 Princes Motorway detour route, which will take about an hour.
A release from Heathcote MP Lee Evans said Transport for NSW "is working with schools and bus providers to coordinate these services and will update the community within the next fortnight"
During the road closure two existing weekday trains travelling to Central will temporarily stop at Stanwell Park.
In the afternoon one existing service travelling from Central will make a stop at Stanwell Park.
Rail commuters in Stanwell Park will be able to catch a 20-seat shuttle bus to and from the station, between 6am and 9pm on weekdays, 7.30am and 6.30pm on Saturdays and 8.30am and 5pm on Sundays.
Buses will run every 10-15 minutes in peak times and 15-20 minutes at other times.
They will be timed to arrive at the station ahead of each train and will operate on demand between train services.
Helensburgh residents can catch the existing Route 15 bus to Helensburgh station.
The release from Mr Evans said issues around COVID-19 will be taken into account during the closure.
"Transport for NSW is following the directives of NSW Health and will continue to keep the community updated in relation to any changes that may occur to planned work as a result of COVID-19," Mr Evans' statement read.
"Emergency services will ensure current service levels are maintained during this work."