Speed Limits for Heavy Vehicles in Victoria

The 100 km/h Heavy Vehicle Cap

Victoria sets a hard ceiling of 100 km/h for heavy vehicles with a Gross Vehicle Mass (GVM) over 4.5 tonnes. This applies on every road where the posted limit is 100 km/h or higher, even where the general car limit is 110 km/h (for example the Hume Freeway). The cap is not advisory — it is a fixed rule under the Victorian Road Safety Road Rules and the NHVR's Heavy Vehicle National Law administration. A heavy rigid truck reading a 110 km/h sign on the Calder Freeway must still hold its speed at or below 100 km/h, and an operator who fits a speed limiter set above 100 km/h is breaching HVNL mass and vehicle standards.

The rule exists because a loaded rigid truck has roughly four to six times the kinetic energy of a car at the same speed, braking distance roughly doubles from 100 to 110 km/h, and the probability of rollover in a steering correction rises sharply above 100 km/h. Examiners test the 100 km/h figure, the 4.5t threshold, and the fact that the cap binds even when the sign says 110 km/h.

Built-up Areas: The 50 km/h Default

Where there are buildings next to the road or street lighting at regular intervals and no speed sign, the default urban speed limit is 50 km/h. Outside a built-up area the default is 100 km/h. The 50 km/h default is the one most drivers underestimate — it is not posted on every street, it simply applies by default. A heavy rigid driver turning off a signed 80 km/h arterial into a local street with no speed sign must drop immediately to 50 km/h, not assume a higher limit.

40 km/h Zones: Shops, Schools, and Emergency Scenes

Victoria uses 40 km/h as a safety speed for vulnerable-road-user zones. The main 40 km/h situations are:

School zone times in Victoria are typically 8:00-9:30 am and 2:30-4:00 pm on school days, but the only reliable trigger is the flashing 40 km/h sign — if it is flashing, you are at 40 km/h, holidays or not.

Roadwork Zones

Roadwork zones carry a signed temporary speed limit that overrides every default. A 60 km/h or 40 km/h temporary sign inside an orange work-zone frame is law, not a suggestion, and Victoria Police and Transport Safety Services (TSS) enforce it whether or not workers are present. The common trap is the off-peak driver who sees cones but no workers and assumes the temporary limit is advisory — it is not. The temporary limit is set for worker safety and for the changed road geometry (narrow lanes, sharp edge drops, loose surface), not only for moving machinery.

Worked Speed Scenarios

Speed-Limiter and Enforcement Notes

Most heavy rigid trucks over 12t GVM used in a fatigue-regulated operation must have a speed limiter set to a maximum 100 km/h. The limiter is an engine-management control — it cannot raise speed above 100 km/h, and a tampered or non-functioning limiter is a separate HVNL offence carrying demerit points and on-the-spot defect notices. Victoria Police mobile speed cameras and point-to-point average-speed cameras on the Hume and Western highways both calculate heavy vehicle speed against the 100 km/h cap, not the 110 km/h car limit.

Common Exam Traps

• A sign reading 110 km/h does not mean 110 km/h for a heavy rigid. The 100 km/h cap is fixed at 4.5t GVM, not at 12t.
• A 40 km/h school zone flashing at 3:15 pm on the last day of term still applies — the flashing sign is the law, not the school calendar.
• A 40 km/h emergency-scene rule applies within 50 m of a stationary emergency vehicle with red/blue flashing lights. You must slow to 40 km/h even if you cannot see workers or police.
• Roadwork limits stay in force even when no workers are visible; they exist for narrowed lanes and loose surface as well as for machinery.
• The 50 km/h built-up default applies where there is no sign — do not assume a higher limit on an unsigned local street.
• Average-speed (point-to-point) cameras compare your time over a long segment to the 100 km/h cap, so a single burst above 100 km/h between two cameras will still be detected even if your instantaneous speed was under 100 km/h at each camera.