
The Mt Ousley Interchange taking shape – looking east towards Mt Ousley Road (July 2025). Photo: Transport for NSW.
Motorists have been warned the speed limit on a section of the M1 Princes Motorway at Mt Ousley has dropped to 60 km/h for the next 18 months.
The temporary speed reduction from 80 km/h will be in place on a 1.8 km section of the motorway’s southbound lanes.
A Transport for NSW spokesperson said the changes were due to construction work on the Mt Ousley Interchange.
“Due to an increase in heavy vehicle movements, machinery and workers in close proximity to the M1 Princes Motorway, a temporary speed reduction is being put in place,” the spokesperson said.

The section of the M1 Princes Motorway where the speed limit has dropped from 80 km/h to 60 km/h. Image: Transport for NSW.
As of Monday (8 September), the speed limit for light vehicles has been reduced to 60 km/h, while the speed limit for heavy vehicles remains at 40 km/h and then 60 km/h, down from 80 km/h.
The speed reduction will be in force from 7 am Mondays until 5 pm Fridays.
Reduced speed limits will not be in place during weekends, public holidays and peak holiday periods.
Meanwhile, NSW Roads Minister Jenny Aitchison said the government had introduced legislation which would remove worksite speed limits outside construction speed hours where it was safe to do so.
Currently, construction speed limits remain in effect outside of construction hours.
“While some road and lane closures do warrant ongoing speed reductions for the purposes of safety, it is not uncommon for drivers to have to slow down on an unobstructed road for work that is not taking place,” Ms Aitchison said.
“The Transport Legislation Amendment Bill 2025 presented to parliament on Wednesday (10 September) requires all road authorities including councils and their contractors undertaking roadworks to install, maintain and remove roadwork speed limit signs in compliance with a standard to be published by Transport for NSW in the gazette.
“This is a common sense approach that applies where there is a roadwork area, but clearly no road workers in the middle of the job. If there is an unobstructed road and it is safe to do so motorists will be able to return to the normal driving conditions.”
It is expected the new legislation will be finalised by the end of the year and be implemented in 2026.