Length

Under the Notice, only a B-double combination vehicle is exempt from the dimension requirements under Schedule 6, section 3 of the MDL. The eligible B-double combination must not exceed 27.5m in length and must have an S dimension no longer than 20.6m in length (Figure 1). 

Transportation of livestock only

An eligible vehicle combination must be used for the transportation of livestock to be defined as an eligible vehicle under the Notice. The load must be entirely composed of livestock. No other type of load may be transported. 

Certified Road-Friendly Suspension (RFS)

Certified Road-Friendly Suspension (RFS) reduces the impact of laden axles on road pavements and most bridge structures.

An eligible vehicle must have functioning certified RFS fitted to each of the following axle groups:

• Dual-drive tandem axle group.
• Tri-axle group on any trailer.
• Tandem axle group on any trailer forming part of a road train.

For additional information about certified RFS, refer to Vehicle Standards Bulletin (VSB) 11 - Certification of Road-friendly Suspensions.

Please note that leaf-spring systems can operate under the Notice provided they are Vehicle Standards Bulletin (VSB) 11 compliant. 

Mass limits

Axle mass limits

An eligible vehicle must not exceed the following axle mass limits listed in Table 2:

Table 2: Axle mass limits

Axle group/tyres	Axle	Axle/vehicle requirements	Tyre section width	Mass limit (t)
Steer axle		Default limit	N/A	6.0
		Complying steer axle	Suitability rated	6.5
		Road train steer axle	295–375 mm	6.5
			At least 375 mm	7.1
Steer axle Euro VI vehicle (prime mover and semitrailer or B-double)		Single steer axle	N/A	6.5
		Complying steer axle		7.0
Twinsteer axle group Single tyres		Non-load-sharing suspension system	N/A	10.0
		Load-sharing suspension system	N/A	11.0
Twinsteer axle group Single tyres Euro VI vehicle (prime mover and semitrailer or B-double)		Euro VI	N/A	11.5
Dual-drive tandem axle group		Dual tyres on all axles	N/A	17.3
Dual-drive tandem axle group Euro VI vehicle  Mass transfer allowance (prime mover and semitrailer or B-double)		Dual tyres on all axles	N/A	17.8
Tandem axle group on any trailer forming part of a road train		Dual tyres on all axles	N/A	17.3
Tri-axle group on semitrailer forming part of a prime mover towing a semitrailer or B-double		Dual tyres on all axles	N/A	25.0
Tri-axle group on any trailer forming part of a road train		Dual tyres on all axles	N/A	23.0

Total combination mass

An eligible vehicle must not exceed the following total mass limits listed in Table 3:

• A combination consisting of a prime mover and a semitrailer 53.3t.
• A combination that is a B-double must not exceed 73.8t.
• A combination that is a road train must not exceed 143.3t.

D rating of fifth wheel couplings and kingpins on B-doubles

The D rating for a fifth wheel coupling or kingpin in a B-double combination must not be less than 119kN as shown in Figure 2.

Vehicle configuration and axle requirements

• The prime mover of an eligible vehicle must have a dual-drive tandem axle group.
• Any semitrailer that is part of a prime mover towing a semitrailer or a B-double must have a tri-axle group.
• All axles on an eligible vehicle other than the steer axle must have dual tyres.
• Any trailer forming part of a road train must have either a tandem axle group or tri-axle group, in the trailer configuration as specified in the Notice.
• All eligible vehicles must have either a single or twinsteer axle group. 

Braking requirements for road trains

Most braking system requirements are made by the ADR to which the vehicle was constructed. A road train must continue to comply with those requirements.  

The VS Regulation makes some additional requirements that apply to road train combinations. These include ensuring there is sufficient air pressure available in the braking system.  

The ADRs have also mandated:  

• anti-lock braking systems to be fitted on prime movers built from 1 January 2015
• vehicle stability control to be fitted on prime movers built from 1 July 2020
• rollover control systems to be fitted on heavy trailers built from 1 November 2019. 

The ADRs' requirements apply to heavy vehicles operating in any state or territory in Australia. 

Mechanical couplings and ratings for road trains  

Mechanical couplings are the devices that connect one component vehicle of a combination to another. They include:  

• fifth wheels, king pins and turntables  
• pin-type couplings and drawbar eyes on converter dolly couplings.  

Eligible road trains are defined in the Notice partly by the types of mechanical couplings with which they are fitted. A key difference between coupling types is their capacity to resist roll between the connected vehicles.  

• Fifth-wheel assemblies that utilise two rotating plates are considered to be roll-coupled connections.  
• Pin-type couplings and drawbar eyes - a feature of converter dollies - are not considered to be roll-coupled. The pin-type connection to the towing (forward) vehicle offers lesser resistance to roll. 

Attachment of couplings and drawbar eyes on road trains

A drawbar-type coupling, or drawbar eye, used in a road train must be built and positioned so that:

• when the road train is moving, the drawbar can move at least 15º upwards or downwards from the position it occupies when the road train is parked on level ground; and
• the pivot point of the coupling is not more than 300mm forward of the rear of the trailer to which it is attached; and
• it is at a height of at least 800mm, but not more than 950mm, when the road train is unloaded and parked on level ground.

Key road train trailer couple strength requirements of ADR63/00

All road train trailers built from July 1991 onwards must comply with Australian Design Rule 63/00 - Trailers Designed for Use in Road Trains. ADR 63 requires that they be equipped with mechanical couplings meeting the standards and strength requirements shown in Table 8.

For road train trailers built before July 1991 and not subject to ADR 63/00, requirements made in the VS Regulation apply. Those include complying with the following

Australasian Standards and updated/later versions of these:

• AS 2175-1990: Articulated Vehicles – Kingpins
• AS 2213-1984: 50mm Pin-Type Couplings and Drawbar Eyes for Trailers
• AS/NZS 4968.1:2003: Heavy road vehicles –Mechanical coupling between articulated vehicle combinations.

These Australasian Standards describe a method to - and require operators to - calculate coupling strength requirements (minimum D-values). Example calculations are shown in Table 5. Alternatively, values no less than those required by ADR 63/00 and shown in Table 4 are acceptable.

Both single steer and twinsteer variants are eligible to operate on some of the networks in Table 6, so long as they comply with the described:

• combination type (e.g. B-double or AB-triple) 
• combination length (e.g. 36.5m in length
• trailer axle configuration (e.g. 3-2-3 or 3-2-3-3).

For example, a twinsteer A-double (3-2-3) as well as a single steer A-double (3-3-3), both of which are up to 30m in length, may operate on the South Australia Livestock Loading Scheme 30.0m A-double Network. 

However, a twinsteer AB-triple (3-2-3-3) and a single steer AB-triple (3-3-3-3), despite both being 36.5m in length, operate on two different networks, since their trailer axle configurations vary.

A single steer AB-triple (3-3-3-3) and a twinsteer AB-triple (3-3-3-3), with varying lengths of 42m and 44m, operate on two different networks, since their combination lengths vary.

27.5m long B-doubles transporting livestock

A B-double may operate under the PBS level 3A network and up to 27.5m long for the transportation of livestock from the Western Australia/South Australian border to Dublin, South Australia via the following route:  

• Eyre Highway from the Western Australia Border to Port Augusta; then
• Victoria Parade, Port Augusta; then
• Augusta Highway; then
• Port Wakefield Highway to the intersection of Carslake Road, Dublin; then
• Carslake Road, Dublin.

A B-double must unload all livestock at the feedlot on Carslake Road, Dublin and end its journey there. An unladen B-double may return using the reverse route to the Western Australian border (Carslake Road, Dublin to the Eyre Highway, Western Border).

Note: The intent of this section is to allow a 27.5m long B-double to transport livestock from the Western Australian border to the feedlots in Dublin, South Australia by a specific route, then return by the same route. It is not intended to provide access to any other route or any other purpose in South Australia.

• Combinations with more than two trailers are strictly prohibited along the South Eastern Freeway.
• Maximum mass limit - 73.3t.
• Maximum length limit - 26m.

Network access conditions may apply to eligible vehicles on the South Australian network:

• Local road manager conditions (Table 5); and
• Restricted structures (Table 6); and
• Unconsented level crossings (Table 7).

Operators should also consult the South Australia Height Clearance Map and Limited Access Locations Information Bulletin on the Approved areas or routes page of the South Australia Government’s website.

Restricted structures

Heavy Vehicle - Road Operations Access Map (HV-ROAM)

Prior to commencing any journey in South Australia, operators should refer to the Heavy Vehicle – Road Operations Access Map (HV-ROAM) page on the South Australian Government website to assist with journey and route planning. 

HV-ROAM should be used alongside the NHVR National Network Map and Traffic SA. 

For further information about the map, please visit the Heavy Vehicle – Road Operations Access Map (HV-ROAM) webpage.

The restricted structures in Table 6 apply to all eligible vehicles operating under the Notice.

Note: The structure location column in Table 6 is hyperlinked to the structure map location.

Unconsented level crossings

The following level crossings require a permit from the rail manager to cross. 

• Corporation of the Town of Walkerville
• City of Victor Harbor

Prior to commencing any journey, operators should review traffic alerts, road closures, travel delays, and other traffic advisory information for participating jurisdictions.

Table 8 provides details and links to official traffic advisory services for each participating jurisdiction. For more information about a particular service, contact the relevant jurisdiction or department via the contact details listed on the service webpage.

Access permit applications are required for heavy vehicles that don’t comply with the conditions set out in a notice and when accessing routes that aren’t covered on an approved network.

The following pages provide useful information and resources for submitting access permit applications:

• Do I need a permit?: Information and resources for determining whether a road access permit, or a Notice is required to operate on Australian roads.
• Access permit application process: Information, resources, and instructions for submitting a valid access permit application.