Heavy vehicle road rules

As a professional driver, it’s your responsibility to know the roads rules that apply to all vehicles, especially heavy vehicles.

Speed limits

In NSW the maximum speed limit for a vehicle more than 4.5 tonnes Gross Vehicle Mass (GVM) is 100 km/h.

For certain road conditions, special speed limit signs may be posted for trucks, road trains and buses. You must not drive at a speed greater than the speed shown on the sign.

More information about speed limits for heavy vehicles.

Driving in wet conditions

Wet roads reduce tyre grip and can result in loss of control.

You should drive at a speed that allows you to brake gradually and stop within the distance you can see. The safe speed for your vehicle and its load may be much lower than the posted speed limit.

To avoid skidding, slow down when approaching corners and select an appropriate gear to maintain vehicle control without the need for braking.

Intersections and turning

Trucks and buses need more space to turn wide at intersections.

More information about making turns in a heavy vehicle.

Level crossings

It takes heavy vehicles and buses longer to clear a level crossing than other vehicles so make sure you allow extra time to clear the tracks safely.

There may not be enough room on the other side of the crossing to stop without your vehicle hanging over the tracks. Know the length of your vehicle and always check ahead before crossing so you can assess the situation. Never cross unless your vehicle can clear the tracks completely.

Your view may be restricted on the left hand side of the vehicle's cabin, be especially aware when the road crosses the track on an angle.

A wide or turning heavy vehicle may damage level crossing signs or signals. Report any damage to the authorities immediately as this will affect the safety of other road users.

Drivers must be aware of conditional access requirements when travelling over level crossings. See Restricted Access Vehicle (RAV) maps and lists.

Heavy vehicles carrying high loads or vehicles fitted with long aerials need to be aware of overhead wiring height restrictions at level crossings in electrified areas.

If you are travelling over a level crossing, ensure your vehicle has adequate ground clearance to avoid your vehicle bottoming out on the crossing or damaging the tracks. If this occurs, leave your vehicle, go to a safe place and call the Police immediately on 000.


When reversing a heavy vehicle, you must:

  • Activate hazard warning lights before starting to reverse
  • Avoid unnecessary reversing. Plan ahead to use the shortest possible reversing distance
  • Use a helper to guide you whenever possible. You should be able to see the guide who should have a clear view of where your vehicle is going
  • Get out and have a look if you are not sure what is behind you
  • Always reverse your vehicle into position in a driveway or loading dock.

Although you may need to hold up traffic while you reverse, it is much safer to drive forward into traffic as you leave.


There are special problems associates with overtaking while driving a heavy vehicle.

It is very important to watch for small vehicles, such as motorcycles. Before pulling out, check your mirrors and glance down to check for vehicles below your cabin. Air movement caused by a large vehicle travelling fast can force a small vehicle off the road, or draw it into the side of a larger vehicle.

Being overtaken

If it is safe, move into the left lane to allow faster moving traffic to overtake.

It is illegal and dangerous to direct following vehicles to overtake, using your hand or the indicator. You may be encouraging an inexperienced driver to attempt an unsafe move.

Lane changing

It is very important to check that the road is clear when you want to change lanes, or when lanes merge. You also need to check before leaving the kerb and before turning.

You must look in the appropriate mirrors and do blind spot head checks before making any of these moves. In a heavy vehicle it is also essential to check down the side door in the cabin.

Restricted areas for road trains and B-doubles

All approved routes are listed in the road train permit notice, and appear on the road train map. You must carry all required permit notices.

B-doubles can operate on all approved road train routes as well as on the state-wide network of B-double routes. You must carry the required permit notices.

Height and length limits

For detailed information see heavy vehicle road access.

Maximum weight of a heavy vehicle road sign

Light traffic roads

If weight restriction sign is displayed for a road, you must not use that road if the total weight of your vehicle, including its load, is the same as or heavier than the weight shown on the sign.

Load limit sign

You must not drive past a BRIDGE LOAD LIMIT (GROSS MASS) sign or GROSS LOAD LIMIT sign if the total of the gross mass (in tonnes) of your vehicle, and any vehicle connected to it, is more than the gross mass indicated in the sign.

NO TRUCKS road sign

No trucks sign

Drivers of long or heavy vehicles, except buses, must not drive past a NO TRUCKS sign unless the vehicle is equal to or less than the mass or length specified on the sign.

When the sign does not provide detailed information, no truck (ie GVM greater than 4.5 tonnes) is permitted to drive past the sign, unless the drivers’ destination lies beyond the sign and it is the only route


Trucks must enter sign

Heavy vehicles drivers must enter the area indicated by information on or with this sign.

Standing and parking

Heavy vehicles (4.5 tonnes or more GVM) or long vehicles (7.5 metres or longer) must not stop on a length of road outside a built up area, except on the shoulder of the road. In a built up area they must not stop on a length of road for longer than one hour (buses excepted).

For more information on where vehicles can stand or park, see the Road Users Handbook

Warning triangles

A vehicle, or a vehicle and trailer, with a GVM of more than 12 tonnes, must carry three portable warning triangles to use if the vehicle breaks down.

If a vehicle required to carry warning triangles stops, or the load being carried by the vehicle falls onto the road and is not visible for 200 metres in all directions, the driver must put:

  • The first triangle 50-150m from the front of the vehicle or fallen load
  • The second triangle 50-150m from the rear of the vehicle or fallen load
  • The third triangle at the side of the vehicle or fallen load, in a position that gives sufficient warning to other road users of the position of the vehicle or fallen load
Truck lane sign

Truck and bus lanes

Where a truck lane is marked with a sign, trucks more than 4.5 tonnes GVM must use these lanes.

Bus lane sign and buses only lane sign

Bus and bus only lanes are marked by signs, or by lane markings on the road.

Public buses constructed principally to carry persons and equipped to seat more than eight adults, including the driver, and used to convey passengers for hire or reward, or in the course of trade or business, may use these lanes.


Specific rules apply to buses


To minimise the risk of fire:

  • Make regular checks of the vehicle during your trip
  • Follow recommended vehicle operating rules
  • Check the instruments and mirrors as part of your regular scanning routine.

If there is a fire in your vehicle:

  • Stop it well away from anything else which may burn
  • Notify emergency services – dial 000
  • Use the correct fire extinguisher
  • If the trailer is on fire, and it is safe to do so, uncouple the prime mover and move it away
  • If the engine is on fire, try not to open the bonnet any more than necessary. Spray the fire extinguisher through louvers, or from the underside of your vehicle
  • Where the load is on fire in a van or box trailer, open the doors slowly and only far enough to let you use the extinguisher properly.

Vehicle monitors

Vehicle monitors are devices which automatically record details about the operation of a vehicle at all times.

See vehicle monitors for detailed information.

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