Default and posted limits
Where there is no speed-limit sign, the default is generally 50 km/h in a built-up area and 100 km/h on other roads. A built-up area is identified by features such as closely spaced buildings and street lighting—not simply by whether the road feels urban.
A posted speed sign replaces the default for that section. Variable electronic limits and temporary roadwork limits must also be obeyed while displayed.
Licence-specific maximum speeds
NSW learner and P1 drivers must not exceed 90 km/h. P2 drivers must not exceed 100 km/h. The lower licence limit continues to apply even when the road sign allows a higher speed.
A driver must also comply with any lower posted limit. Think of the lawful maximum as the lowest limit that applies to the driver, vehicle and road at that moment.
On a 110 km/h road, an L or P1 driver is still limited to 90 km/h and a P2 driver to 100 km/h.
School, shared and work zones
School-zone signs display the limit and the times when it operates. Read the sign at that location rather than relying on memory. Remain alert for children before and after the signed section as well.
Shared zones are commonly signed at 10 km/h and drivers must give way to pedestrians. At roadworks, obey temporary signs, traffic controllers and changed lanes even when workers are not immediately visible.
Drive below the limit when necessary
Reduce speed when rain, fog, darkness, gravel, curves, congestion or limited sight distance make the posted maximum unsafe. You need enough visible distance to identify a hazard, react and stop.
A yellow advisory-speed sign is not the same as a regulatory limit, but it is a strong warning that the approaching curve or hazard needs a lower speed in good conditions—and possibly less in poor conditions.