This page provides information on the application of mass or dimension conditions to Class 1 heavy vehicles under Schedule 8 of the Heavy Vehicle (Mass, Dimension and Loading) National Regulation (MDL). 

These conditions generally apply to Class 1 heavy vehicles operating under a notice or permit.

In some cases, Schedule 8 conditions can be applied or exempted to a vehicle or combination via a notice or permit. For example, an oversize Class 3 notice or permit may apply Schedule 8 conditions as if the vehicle or combination was a Class 1 vehicle. 

Operators must check the conditions of operation in their access instrument (notice or permit) to check if there are any exemptions or additional requirements to those specified in Schedule 8 of the MDL.

General information

To assist operators, we have provided a brief explanation of some of the common conditions in Schedule 8 of the MDL. 

• Smallest practical dimension
• Warning lights, delineators, signs and flags
  • Oversize signs
  • Warning lights
  • Warning flags
  • Warning lights and delineators
• Headlights
• Night travel
• No travelling in low visibility
• Minimum following distance
• Allowing overtaking
• Assessing routes
• Communication between drivers
• Towing a low loader dolly with an unladen low loader

Smallest practical dimension

An oversize vehicle must be kept to the smallest practicable dimensions, with any booms retracted when unladen.

Refer to the Loading webpage for more information on loading requirements.

Carrying goods in addition to a large indivisible item

A load-carrying vehicle must not carry more than one large indivisible item unless:

• the vehicle, together with its load, complies with the general mass limits; and
• the vehicle carrying more than one large indivisible item does not cause the vehicle together with its load to exceed a prescribed dimension requirement that would not be exceeded if the vehicle carried only one of the large indivisible items.

A load-carrying vehicle carrying one or more large indivisible items must not carry any other goods unless:

• the vehicle, together with its load, complies with the general mass limits; and
• the other goods are contained within the limits set by the prescribed dimension requirements.

For more information, refer to& Multiple items on Class 1 load-carrying vehicles.

Warning lights, delineators, signs and flags

Oversize signs

An oversize heavy vehicle that, together with its load, is wider than 2.5m or longer than 25m must have:

• a warning sign attached to the front of the vehicle; and
• a warning sign attached to the rear of the vehicle, or if a load projects from the rear of the vehicle, to the rear of the load.

An oversize vehicle that, together with its load, is not wider than 2.5m and whose length is more than 22m but not mor than 25m, must have a warning sign attached to the rear of the vehicle, or if a load projects from the rear of the vehicle, to the rear of the load.

The warning sign on an oversize vehicle must be at least 1200mm long and at least 450mm high. The length of the sign may be split into two parts, in which case the combined length of its parts must be at least 1200mm.

A warning sign on an oversize vehicle must have a face showing:

• the word OVERSIZE, in black capital letters and in typeface Series C(N) complying with AS 1744 Forms of Letters and Numerals for Road Signs Note – AS 1744 Forms of Letters and Numerals for Road Signs may be purchased from Standards Australia at www.standards.org.au; and
• the letters must be at least 200mm high and at least 125mm from the top and bottom of the warning sign.

If the length of the warning sign is split into two parts:

• the word OVER must be on the left part, and the word SIZE on the right part; and
• there must be no border between the two parts; and
• both parts must be mounted at the same height.

A warning sign on an oversize vehicle must be fitted horizontally. The lower edge of the warning sign must be:

• above the bottom bumper bar, or
• if there is no bumper bar, at least 500mm above ground level.

The face of a warning sign on an oversize vehicle must have:

• a yellow surface complying with Class 1 or 2 of AS 1906 ‘Retro-reflective Materials and Devices for Road Traffic Control Purposes’; and
• a black border that is at least 20mm wide and, unless the sign is made with a box edge, whose outermost edge is at least 10mm in from the edge of the sign
• its manufacturer’s name or trademark; and
• the brand and class of material used for the warning sign’s surface, permanently marked in letters at least 3mm but no more than 10mm high on any visible part of the sign.

A warning sign may be made of flexible, weatherproof material if the sign is:

• held taught; and
• clearly visible; and
• unlikely to become dislocated, furl; and
• maintained so it can be easily read by other road users. 

Example of a warning sign of an oversize vehicle or combination:

Warning lights

A warning light attached to an oversize vehicle, when switched on, must:

• emit a yellow-coloured light of rotating and flashing effect; and
• flash between 120 and 200 times a minute and have a power of at least:
  • if LED technology is used— 24W, or
  • if another technology is used—55W; and
  • not be a strobe light.

A warning light attached to an oversize vehicle must be:

• clearly visible at a distance of 500m in all directions, or
• supplemented by one or more additional warning lights so that the light emanating from at least one of them is clearly visible at a distance of 500m in any direction.

Warning flags

An oversize heavy vehicle that, together with its load, is wider than 2.5m or longer than 25m must have:

• four brightly coloured red, red and yellow, or yellow flags, each at least 450mm by 450mm, fixed as follows:
  • a flag must be attached at each side of the front of the vehicle or, if a load projects from the front of the vehicle, at each side of the front of the load.
  • a flag must be fixed at each side of the rear of the vehicle or, if a load projects from the rear of the vehicle, at each side of the rear of the load.

Warning lights and delineators

If a load projects more than 150mm beyond a side of an oversize vehicle, and the projection is less than 500mm thick from top to bottom:

• a warning light must be attached to the vehicle; and
• two delineators must be attached to the projection on each side of the vehicle on which the load projects more than 150mm in the following way:
  • at least one delineator must be attached to the front of the projection so that its reflective surface is facing forward of the vehicle; and
  • at least one delineator must be attached to the rear of the projection so that its reflective surface is facing rearward from the vehicle.

Delineator means a yellow, rigid piece of material that:

• is at least 300mm long and at least 300mm wide
• complies with Class 1, 2, 400 or 100 of AS 1906 Retro-reflective Materials and Devices for Road Traffic Control Purposes.

Warning lights for wide vehicles used in daytime

A warning light must be attached to the vehicle while it is being used in the daytime, if the oversize vehicle is, together with any load, wider than 3m.

Side and rear markers and warning lights for oversize vehicles used at night

If an oversize vehicle is being used at night side markers must be displayed:

• not more than 2m apart along the total length of each side of the vehicle and any load projecting from the front or rear of the vehicle; and
• at each corner of any load projecting from the front or rear of the vehicle; and
• 2 rear markers must be fitted to the rear of any load projecting from the rear of the vehicle, within 400mm of each side of the load and at least 1m but not more than 2.1m above the ground; and
• a warning light must be attached to the vehicle if it, together with any load, is wider than 2.5m or longer than 22m.

Rear markers: Means red lights known as ‘rear markers’.

Side markers: Means lights showing yellow to the front and red to the rear and are known as ‘side markers’.

Headlights

An oversize vehicle is required to have its low-beam headlights on while it is being used in the daytime.

low-beam, in relation to a headlight fitted to a heavy vehicle, means the light is built or adjusted so that, when the vehicle is standing on level ground, the top of the main beam of light projected is:

• not higher than the centre of the headlight when measured 8m in front of the vehicle; and
• not more than 1m higher than the level where the vehicle is standing when measured 25m in front of the vehicle.

Travel restrictions at night

An oversize vehicle that, together with any load, is wider than 3.1m or longer than 22m, must not, while being used at night:

• travel outside an urban area; or
• travel in an urban area without being accompanied by a pilot vehicle.

No travelling in low visibility 

An oversize vehicle or combination must not begin to travel if:

• due to circumstances such as fog, heavy rain, smoke, dust or insect plague, visibility is less than 250m in the daytime; or 
• the headlights of a vehicle approaching within 250m could not be seen at night.

If an oversize vehicle or combination is already travelling when visibility is reduced to, or below the level mentioned above, the vehicle’s driver must drive the vehicle into the nearest safe parking area and wait until visibility improves beyond that level before continuing to travel.

Minimum following distance for all oversize vehicles

The driver of an oversize vehicle or combination must maintain a distance of at least 200m from another oversize vehicle or combination travelling in front of it, unless:

• overtaking, or
• driving on a multi-lane road, or
• driving in an urban area.

Allowing overtaking

Where the oversize vehicle or combination is travelling on a road that does not have a separate overtaking lane, the driver of the oversize vehicle or combination must at regular intervals, as reasonably practical, move the vehicle off the road to allow following vehicles to overtake.

Assessing routes

Before an oversize vehicle is driven along any road or road related area, Its driver and operator must be satisfied that the route has been assessed and the vehicle can be driven without causing:

• disruption to telecommunication, electricity, rail, gas, water or sewage services (relevant services); or
• damage to a road (including a bridge), structure, rail crossing or tree (relevant property).

Communication between drivers

All persons involved in the operation of an oversize vehicle or combination and any other entity associated with the movement must ensure they have the appropriate equipment to maintain two-way radio communication between all pilots, escorts, police officers and the oversize vehicle.

An oversize vehicle and any accompanying pilot vehicle or escort vehicle must have a device that allows the drivers to communicate effectively with each other.

Towing a low loader dolly with an unladen low loader

A low loader dolly must not be towed in combination with an unladen low loader unless the combination is 2.5m wide or less and there are exceptional difficulties in loading or unloading the dolly due to the nature of the site or because of the short distance to be travelled.