Definitions

Unless otherwise stated, words and expressions used in this Operator’s Guide have the same meanings as those defined in the HVNL and the Notice.

Term	Definition
General Mass Limits (GML)	The heavy vehicle general axle mass limits prescribed in the HVNL that apply to public roads in Australia unless otherwise limited by load restriction signs.
General access	When a heavy vehicle complies with mass and dimension requirements and does not require a notice or permit to operate on the road network. These vehicles have general access to the road network subject to the operation of the HVNL and the road rules of the relevant participating jurisdiction.
Higher mass limits (HML)	A mass exception under the HVNL which allows higher mass limits on approved routes for particular vehicles or vehicle combinations dependent on other conditions being met (e.g. IAP and/or road friendly suspension may need to be fitted to the vehicle).
Load-sharing suspension system (of an axle group)	Means a suspension system: built to divide the load between the tyres on the group so no tyre carries a mass more than 10% above the mass it would carry if the load were divided equally; and with effective damping characteristics on all axles of the group
Semitrailer	A typical (conventional) semitrailer has a single axle or an axle group towards the rear of its load carrying surface.
Total combination mass	The maximum allowable mass limit for a heavy or combination.
Twin steer	A hauling unit that is fitted with a tandem steering axle group.    The tandem steer axle group is equipped with single tyres to both axles and connected to the same steering column. The axles are spaced at least 1m apart but no more than 2m apart.   Figure 1 demonstrates the minimum axle spacing requirements of a prime mover fitted with a twin steer axle group, required to obtain the maximum GML as 11t for load sharing .

Eligible vehicles

This Notice applies to a seven-axle heavy vehicle combination consisting of a prime mover fitted with:

• a twin steer axle group, and
• a tandem drive axle; and
• a single semitrailer fitted with a tri-axle group.

What is twinsteer prime mover? 

A twinsteer prime mover is fitted with a tandem steering axle group.

The tandem steer axle group is equipped with single tyres to both axles and connected to the same steering column. The axles are spaced at least 1m apart but no more than 2m apart. 

Figure 3 demonstrates the minimum axle spacing requirements of a prime mover fitted with a twinsteer axle group, required to obtain the maximum GML as 11t for load sharing .

Conditions

Notices are subject to various conditions to ensure public safety, protect assets and prevent adverse impacts on the community, such as noise, emissions and traffic congestion. See the sections below for specific conditions related to this Notice.

Dimension conditions - Click to expand

General dimensions conditions

There are no dimensional exemptions provided by this Notice. All eligible vehicles must comply with general dimensions applying to the vehicle or combination.

Table 1: General dimension requirements

Type of Dimension	Maximum dimension limit (metres)
Width	2.5m
Height	4.3m for all other combinations
Rear overhang	3.7m or 60% of the wheelbase
Combination length limits	19.0m

Note: For more information on general dimension, refer to the General mass and dimension limits

Trailer length limits

The Notice does not provide an exemption for trailer length. All trailers must comply with the same prescribed trailer dimension limits that apply to the compliant combinations (e.g. the semitrailer length limits in the MDL Regulation shown in Figure 4).

Mass conditions - Click to expand

The Notice provides access for eligible combinations at the following mass limits:

• Mass limits without either Alternative Compliance Accreditation (ACA) - Mass, or Mass Management Accreditation (granted prior to 1 August 2026).
• Mass limits for vehicles enrolled in either Alternative Compliance Accreditation (ACA) - Mass, or Mass Management Accreditation (granted prior to 1 August 2026).
• Mass limits for vehicles enrolled in either Alternative Compliance Accreditation (ACA) - Mass, or Mass Management Accreditation (granted prior to 1 August 2026) with certified road friendly suspension.

Mass limits without ACA - Mass or Mass Management Accreditation

GML applies to all heavy vehicles and is the stated allowable mass for a heavy vehicle axle group unless the vehicle is operating under an accreditation or an exemption under HVNL. Any additional or conditional mass allowed under the Notice may not exceed manufacturer mass limits pursuant to section 8 of the MDL.

This Notice allows the combination to exceed a maximum mass of 47.5t, if fitted with a load-sharing suspension. 

An eligible vehicle under this section has the following mass requirements apply when operating under the Notice:

• maximum total combination mass limit (Table 2);
• individual axles and axle groups (see Table 3);
• total axle spacing mass limits (see Table 4)
• those specified by the vehicle manufacturer;
• individual components (vehicles and trailers).

Table 2: Maximum total mass limits under the Notice

Twin steer prime mover fitted with the following suspension type	Total mass limit (tonnes)
Non-load sharing suspension	46.5t
Load sharing suspension	47.5t

Table 3: Mass limits of individual axles and axle groups

Axle group/tyres	Axle	Axle/vehicle requirements	Tyre section width	Mass limit (t)
Twin steer axle group  Single tyres		Non-load-sharing suspension system	N/A	10.0
		Load-sharing suspension system	Suitability rated	11.0
Tandem axle group		Single tyres on all axles	Less than 375mm	11.0
			375–450mm	11.0
			at least 450mm	14.0
		Single tyres on one axle and dual tyres on the other axle	N/A	13.0
		Dual tyres on all axles	N/A	16.5
Tri-axle group		Single tyres on all axles	Single tyres less than 375mm	15.0
			At least 375 mm	20.0
		Combination of single and dual tyres	Single tyres less than 375mm	15.0
			Single tyres at least 375 mm	20.0
		Dual tyres on all axles	N/A	20.0

Table 4: Axle spacing mass limits – general access

Length of axle spacing (m)		Mass limit (t)
At least	Less than
3.5	3.7	23
3.7	3.8	23.5
3.8	4	24
4	4.2	24.5
4.2	4.3	25
4.3	4.5	25.5
4.5	4.7	26
4.7	4.8	26.5
4.8	5	27
5	5.2	27.5
5.2	5.3	28
5.3	5.5	28.5
5.5	5.7	29
5.7	5.8	29.5
5.8	6	30
6	6.2	30.5
6.2	6.3	31
6.3	6.5	31.5
6.5	6.7	32
6.7	6.8	32.5
6.8	7	33
7	7.2	33.5
7.2	7.3	34
7.3	7.5	34.5
7.5	7.7	35
7.7	7.8	35.5
7.8	8	36
8	8.2	36.5
8.2	8.3	37
8.3	8.5	37.5
8.5	8.7	38
8.7	8.8	38.5
8.8	9	39
9	9.2	39.5
9.2	9.3	40
9.3	9.5	40.5
9.5	9.7	41
9.7	9.8	41.5
9.8	10	42
10	10.5	42.5
10.5	11	43
11	11.5	43.5
11.5	12	44
12	12.5	44.5
12.5	13	45
13	13.5	45.5
13.5	14	46
14	14.5	46.5
14.5	15	47
15	--	47.5

Mass limits for vehicles enrolled in ACA - Mass or Mass Management Accreditation

An eligible vehicle under this section has the following mass requirements apply when operating under the Notice:

• enrolled in either ACA - Mass, or Mass Management Accreditation (granted prior to 1 August 2026);
• total axle spacing mass limits in Table 4, and increased masses specified in Table 5;
• those specified by the vehicle manufacturer;
• individual components (vehicles and trailers).

Table 5: Masses for eligible vehicles enrolled in ACA - Mass or Mass Management Accreditation

Axle group type	Additional mass (t)	Maximum mass with addition (t)
Dual-drive tandem axle group on the prime mover	0.5	17.0
Tri-axle group on the semi-trailer	1.0	21.0

Mass limits for vehicles enrolled in ACA - Mass or Mass Management Accreditation with certified road-friendly suspension (RFS)

An eligible vehicle under this section has the following mass requirements apply when operating under the Notice:

• enrolled in either ACA - Mass, or Mass Management Accreditation (granted prior to 1 August 2026);
• both the drive axle group and trailer axle group are fitted with certified road-friendly suspensions;
• total axle spacing mass limits in Table 6, and increased masses specified in Table 7;
• those specified by the vehicle manufacturer;
• individual components (vehicles and trailers).

Certified Road Friendly Suspension (RFS)

Single axles or axle groups loaded at the higher masses must be fitted with certified Road Friendly Suspension (RFS) systems. RFS reduces the impact of laden axles on road pavements and most bridge structures. 

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

Table 6: Masses for eligible vehicles enrolled in ACA - Mass or Mass Management Accreditation with certified road-friendly suspension

Axle group type	Additional mass (t)	Maximum mass with addition (t)
Dual-drive tandem axle group on the prime mover	0.5	17.0
Tri-axle group on the semi-trailer	2.5	22.5

Table 7: Axle spacing mass limits – restricted network access

Length of axle spacing (m)		Mass limit (t)
At least	Less than
3.5	3.7	23
3.7	3.8	23.5
3.8	4	24
4	4.2	24.5
4.2	4.3	25
4.3	4.5	25.5
4.5	4.7	26
4.7	4.8	26.5
4.8	5	27
5	5.2	27.5
5.2	5.3	28
5.3	5.5	28.5
5.5	5.7	29
5.7	5.8	29.5
5.8	6	30
6	6.2	30.5
6.2	6.3	31
6.3	6.5	31.5
6.5	6.7	32
6.7	6.8	32.5
6.8	7	33
7	7.2	33.5
7.2	7.3	34
7.3	7.5	34.5
7.5	7.7	35
7.7	7.8	35.5
7.8	8	36
8	8.2	36.5
8.2	8.3	37
8.3	8.5	37.5
8.5	8.7	38
8.7	8.8	38.5
8.8	9	39
9	9.2	39.5
9.2	9.3	40
9.3	9.5	40.5
9.5	9.7	41
9.7	9.8	41.5
9.8	10	42
10	10.2	42.5
10.2	10.3	43
10.3	10.5	43.5
10.5	10.7	44
10.7	10.8	44.5
10.8	11	45
11	11.2	45.5
11.2	11.3	46
11.3	11.7	46.5
11.7	12	47
12	--	47.5

Local mass requirements  

Operators must also comply with local mass requirements. These are shown on the maps detailing road train access. These local requirements reflect limitations of specific road infrastructure (e.g. a bridge load limit). 

Other conditions and additional information

Third party approvals

Gazette notices, permits and some jurisdictional laws may require third parties and other entities to provide permission for a vehicle to travel if it exceeds certain mass or dimension limits.

Operators must secure all approvals from third parties such as electricity/utility companies, rail authorities and other third parties as part of their heavy vehicle operations.

For more information, visit the Third party approvals page.

Complying with the HVNL

Unless otherwise exempted by the Notice or this Operator's Guide, operators must ensure their vehicle or combination complies with the:

• Australian Design Rules (ADRs); and,
• Heavy Vehicle National Law (HVNL); and,
• Heavy Vehicle (Mass, Dimension and Loading) National Regulation (MDL); and,
• Heavy Vehicle (Vehicle Standards) National Regulation (VS Regulation).

Using or permitting another person to use a defective heavy vehicle or a heavy vehicle with unapproved modifications on a road may be an offence.

Failure to comply may result in the driver and/or operator being liable for an offence. Penalties can include infringement notices or prosecution.

Chain of Responsibility (CoR)

Under the HVNL, every party in the Chain of Responsibility (CoR) has a positive duty to ensure the safety of their activities in relation to a heavy vehicle. This duty, known as the “primary duty”, applies to the scheduling, loading and consigning of a vehicle, as well as to its operation on a road.

Safety is broader than the safety of drivers and other road users. It also includes protection of road infrastructure, preventing damage to other vehicles or property, and minimising environmental harm. Substantial penalties may be imposed upon parties who breach this obligation and upon their executives.

For more information on your CoR obligations visit Chain of Responsibility on the NHVR website.

Our Regulatory Advice offers guidance, tips and tools for managing a range of heavy vehicle safety risks.

Loading requirements

To meet the loading requirements, the heavy vehicle must be loaded:

• in a way that load placement does not make the heavy vehicle unsafe or unstable
• in a way that the load is not likely to fall or be dislodged from the vehicle
• using an appropriate system to restrain the load.

Visit the NHVR loading page for more information on load requirements.

The requirement to carry the Notice

Drivers do not need to carry a copy of the Notice. 

Network and mapping

For the purposes of s121 of the HVNL, an area or route specified in the 'Network & Mapping' section of this Operator's Guide is a stated area or route to which this Notice applies. In addition to complying with the conditions stated in this Operator's Guide, operators must ensure compliance with the specific road manager access requirements set out below or in network maps.

In this tab, you will find the approved routes authorised under the Notice. There may also be network conditions pursuant to the stated areas and routes under the Notice. Network conditions relate to road and travel conditions that are not contained within the Notice.

Approved routes covered by the Notice

Under this Notice, eligible vehicles may operate in the areas and on the routes in Tasmania as specified below:

Tasmania network mapping

The Department of State Growth is responsible for publishing and maintaining authorised heavy vehicle road network maps in Tasmania.

Visit Heavy vehicle access to view an authorised network.

Non-participating road managers

Access on local roads for the following non-participating road manager is not approved for an eligible vehicle under the Notice and operators will need to apply for an NHVR permit.

• Launceston Airport

Please note that the above list shows non-participating road managers as at 6 February 2024 and is subject to change.

Specified road manager network requirements

The following section outlines specific road manager network requirements under the Notice, including route conditions, restrictions, and non-participating road managers.

Road manager network requirements in this section may change from time to time and should be reviewed regularly to ensure compliance.

For further information on how to comply with a requirement, please contact the relevant road manager.  

Road managers may publish specific route conditions and restrictions on the approved network map. These must be complied with in addition to any route requirements outlined in this Operator's Guide. If a condition listed in any section of this Operator's Guide conflicts with a route condition or restriction published on an approved network map, the more restrictive requirement applies.

Related notices

There are no current related notices for the Tasmania Class 3 Heavy Vehicle Twin Steer Prime Mover Semitrailer Mass Exemption Notice 2026 (No.1).

A related notice may coincide with the featured notice or provide alternatives for operators to find the appropriate notice to operate.

Resources

All information about the Notice is contained in this Operator’s Guide. Please refer to the tabs for more information about this notice, or contact us with your specific questions.

Note: If you have any feedback on the information provided please contact us at info@nhvr.gov.au

Participating jurisdiction heavy vehicle resources

For more information about operating a heavy vehicle in participating jurisdictions, refer to the following sites:

• Tasmania: Department of State Growth (DSG) - Heavy vehicles

Changes and updates