
The speed limits have changed in response to a government review. Photo: Michelle Kroll.
Four key south-eastern roads have reduced their speed limits in a move aimed at boosting motorists’ safety.
New 80 km/h speed limits have been introduced from today (8 September) on Sutton Road, Mulligans Flat Road, East Tallagandra Lane and Back Creek Road, at locations near Sutton and Gundaroo.
This follows a Transport for NSW (TfNSW) review of speed zones in the area, driven by concerns raised by the community and Yass Valley Council about the existing 100 km/h limits.
The review was a comprehensive process that included site inspections, analysis of the current road environment and road condition, consideration of crash data and traffic volumes.
A TfNSW spokesperson said it was found that existing 100 km/h speed zones did not comply with the NSW speed zoning standard.
A crash analysis of the entire review area also revealed 20 accidents, including two fatalities between 2018 and 2023.
The speed limit will be reduced to 80 km/h on the following four key road sections:
- A 13 km length of Sutton Road from Sutton Village to the existing 80 km/h zone at Gundaroo
- A 9 km stretch of Mulligans Flat Road from the ACT-NSW border to the Sutton Road intersection
- The 5.7 km length of East Tallagandra Lane
- The 9 km length of Back Creek Road.
The roads are often used as alternative routes to the Barton Highway when it is closed.
The TfNSW spokesperson thanked the community for their understanding around the changes.
“Electronic message signs will be installed before and after the changes come into effect and there will be community notices via council and community groups to advise motorists of the new speed limit,” they said last week.
“Speed limits are set to ensure motorists travel at safe and appropriate speeds for the surrounding road environment, and to allow time for drivers travelling at the limit to detect potential hazards and respond by braking effectively.”

The affected roads run between or near Sutton and Gundaroo. Image: Yass Valley Council.
The new speed limit means increased travel times of about two minutes on Sutton Road and 52 seconds on East Tallagandra Lane.
Trips on Mulligans Flat and Black Creek roads are expected to last an extra one minute and 20 seconds each.
The speed zone review was carried out to ensure limits are in line with the NSW Speed Zoning Standard, applying the Safe System approach.
The Safe System approach has been adopted by all Australian jurisdictions to support road safety outcomes in jurisdictional and national road safety action plans.
Motorists are advised to drive according to the conditions and follow the directions of signs and traffic control during the installation of signs.
For the latest traffic updates, motorists can download the Live Traffic NSW App, visit livetraffic.com or call 132 701.