9.1 Traffic Signs: Regulatory, Warning and Heavy-Vehicle Signs

Key Takeaways

  • Traffic signs are about one in seven questions in the published HVKT pool, and almost all of them are sourced from the Road User Handbook rather than the Heavy Vehicle Driver Handbook.
  • Regulatory signs state the law and are usually rectangular black-on-white or a red circle; warning signs are yellow diamonds and the correct answer to them almost always begins with 'slow down and be prepared to'.
  • A sign showing a truck or bus symbol with a speed number is a regulatory sign for truck and bus drivers that must be obeyed, even where cars around you may lawfully travel faster.
  • A low gear sign for heavy vehicles means the gear you choose must be able to control the vehicle's speed on the descent, and a clearance sign means you may only proceed if your loaded vehicle is less than the height shown.
  • A STOP sign requires a full stop even when there is no other traffic, and a STOP or GIVE WAY sign that has been knocked down still has exactly the same legal meaning as the standing sign.
Last updated: August 2026

9.1 Traffic Signs: Regulatory, Warning and Heavy-Vehicle Signs

Quick Summary / Key Rule: Traffic signs are the single largest identifiable block in the published Heavy Vehicle Knowledge Test question pool after general knowledge — roughly one in seven questions. Almost all of them come from the Road User Handbook, not the Heavy Vehicle Driver Handbook. Candidates who study only truck-specific material walk into the test having never revised the material that carries the most questions.

Signs fall into two legal categories, and the distinction decides how you answer. A regulatory sign states a law: disobeying it is an offence. A warning sign tells you a hazard is ahead: it does not by itself impose a speed or a manoeuvre, but ignoring it and then losing control is negligent driving. A large share of the wrong answers on sign questions come from candidates treating a warning sign as if it were a rule, or the reverse.


Regulatory Signs: These Are the Law

Regulatory signs are usually rectangular, black on white, or a red circle/slash for a prohibition.

SignWhat it legally requires
STOPStop at the stop line and give way to all traffic. If there is no painted stop line, stop before and as near as possible to the intersection. You must stop even when there is no other traffic.
GIVE WAYSlow down, be ready to stop, and give way to all traffic.
Speed limit (e.g. 60)You must not exceed that speed. Note the sign is a maximum, never a target.
NO RIGHT TURN / NO LEFT TURNYou must not turn in that direction.
ONE WAYYou may travel only in the direction of the arrow.
KEEP LEFT / left lane unless overtakingYou must stay in or move to the left lane unless you are overtaking, turning right, or the lane is obstructed.
NO STOPPINGYou must not stop your vehicle at the kerb during the times shown.
CLEARWAY (broken yellow edge line)You must not stop during clearway hours, for any reason including a delivery.
T2 / T3 transit laneOnly vehicles carrying the stated minimum number of occupants may use the lane.
Trucks laneTrucks more than 4.5 tonnes GVM must use this lane.
No trucksVehicles over the stated GVM must not enter.
Mobility parking (wheelchair symbol)Only a vehicle carrying a person with disability and displaying a current mobility parking authority may park in that space.

Heavy-vehicle regulatory signs worth memorising

  • Truck and bus speed signs. A sign showing a truck or bus symbol with a number is a regulatory sign for truck and bus drivers which must be obeyed. If it shows 40, a truck or bus must not exceed 40 km/h even though cars around it may lawfully do 80. This catches candidates who assume the truck symbol makes it advisory.
  • Low gear signs. A sign directing heavy vehicles to use low gear on a descent means the gear you choose must be able to control the vehicle's speed on the descent. It is not a suggestion to "consider" a lower gear; it is a requirement that your gear selection actually does the braking work.
  • Bridge and tunnel clearance signs. A clearance sign on the approach to a bridge or tunnel means you may only proceed if your loaded vehicle is less than the height shown. Your height is the height of the vehicle plus its load, and the responsibility sits with you, not the consignor.
  • Load limit signs. These restrict a bridge or road to vehicles under a stated mass. Exceeding a posted load limit is an offence and, on a weakened bridge, a structural risk.

Warning Signs: Diamond, Yellow, Advisory

Warning signs are yellow diamonds with black symbols. They tell you something is ahead and that you should slow down and be prepared. In a heavy vehicle their significance is multiplied, because your stopping distance and your rollover threshold are both far worse than a car's.

Warning signWhat is aheadThe heavy vehicle consequence
Curve / sharp bend, with advisory speedThe maximum safe speed around the curveAn advisory curve speed is calculated for a car. A high-centre-of-gravity truck can roll below the advisory speed.
Winding roadA series of bendsSelect your gear before the first bend, not between them.
Steep descentA steep down-gradeChoose your gear at the top; a heavy vehicle cannot change down safely once it is running away.
Crest / hillYou are approaching the top of a hillKeep left and slow down — you cannot see oncoming traffic and must not overtake.
Dip / humpA sharp depression or hump in the roadSuspension travel and load shift; a long combination can ground out.
Road narrows / divided road endsTwo-way traffic resumesA 2.5 m wide vehicle has very little lateral margin.
One-lane bridge (sign on or near a bridge)The bridge is too narrow for two vehicles to passSlow down and be prepared to give way to vehicles travelling in the opposite direction. This is the published answer — the sign does not require you to stop, and it is not about pedestrians or overtaking.
Narrow (two-vehicle) bridgeThe bridge has only just enough room for two vehiclesSlow down and pay extra attention. Do not sound your horn to warn the other driver, and do not hold your speed.
Slippery when wetReduced grip in the wetBraking distance can double; slow down before the surface, not on it.
Trucks enteringTrucks joining from a side road or quarryExpect slow, heavy vehicles crossing your path.
Children / school crossing aheadChildren may be crossingSlow down and be ready to make a safe stop.
Pedestrian crossing aheadA marked crossing is comingYou must be able to stop, not just slow.
Animals (kangaroo, cattle)Animals on or near the roadSlow down and give them plenty of room; do not swerve at speed in a laden truck.
BicycleWatch for bicycle riders along the roadwayYou must leave a minimum passing distance.
Crossroads / T-intersection aheadAn intersection is approachingReduce speed and watch for vehicles entering.
Traffic signals aheadLights are coming, possibly after a crestBe ready to stop if the lights change.
Roadworks / workers ahead / traffic controller aheadA work zoneSlow to the posted work-zone limit and follow any controller.

[!TIP] The consistent correct answer to "what does this warning sign mean" in the official pool begins with "slow down and…". Warning signs never grant a right of way and never authorise a manoeuvre. If an option says a warning sign lets you do something, it is wrong.


Railway Level Crossing Signs

Level crossings get their own family of signs, and heavy vehicles are the vehicles most likely to be caught on the tracks.

  • Crossing with a STOP sign: stop at all times, then proceed when safe.
  • Crossing with a GIVE WAY sign: slow down, look both ways for trains, and be ready to stop and give way to a train.
  • Flashing signals: stop until the red lights stop flashing, then drive on if it is safe.
  • Boom gates down: you may only begin to cross when the gate is up and the lights have stopped flashing.
  • No signals at all: slow down, be ready to stop, and give way if a train is coming.

A rule that only matters to heavy vehicle drivers: even where the crossing is clear and the signals are silent, do not enter if traffic on the far side is blocking your exit. A 26 metre B-double needs the entire crossing plus its own length of clear road on the other side before it should move.


Working the Sign Questions in the Test

  1. Read the shape and colour first. Red or black-on-white rectangle means it is a law. Yellow diamond means it is a hazard warning.
  2. Ask who the sign is addressed to. A truck or bus symbol narrows the sign to heavy vehicles, and it is usually a regulatory sign — a "must", not a "should".
  3. Reject options that give you permission. Warning-sign answers do not authorise anything.
  4. Reject options that soften a regulatory sign. A STOP sign requires a full stop even when there is no other traffic, and a knocked-down STOP or GIVE WAY sign still has the same meaning as the sign itself.
Test Your Knowledge

A sign showing a truck symbol and the number 40 is displayed on the approach to a steep descent. A car in front of you passes it at 70 km/h and is not booked. What does the sign require of you in a 15-tonne truck?

A
B
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D
Test Your Knowledge

You approach a bridge displaying a clearance sign. Your prime mover is 3.9 metres high but the machine on the low loader takes the loaded height to 4.4 metres. What governs whether you may proceed?

A
B
C
D
Test Your Knowledge

A STOP sign at a quiet rural intersection has been knocked down in a collision and is lying in the grass. What is your legal obligation?

A
B
C
D
Test Your Knowledge

You see a yellow diamond sign showing a curve symbol with '45' underneath while driving a laden semi-trailer. How should you treat the number?

A
B
C
D
Test Your Knowledge

You are approaching a bridge that has only just enough room for two vehicles, and a sign is displayed on the approach. What does the sign require, and what should you do?

A
B
C
D