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Dimension Limits


In recent years the consequences of not complying with the legal dimension limits for heavy vehicles have been spectacularly displayed, with New South Wales’ major roads being blocked by trucks stuck in bridges and tunnels. As a result, the authorities have stepped up enforcement of the limits.

This article describes the dimension requirements, and the consequences of breaching them.

What Are The Dimension Limits?

A vehicle towing one trailer must not be more than 4.3 metres high and 2.5 metres wide. From the point of articulation (pivot joint) to the rear of the vehicle must be no longer than 12.5 metres. For a b-double, the limit is 25 metres, and a road train, 53.5 metres.

The above limits are general limits only. There are exceptions and other special limits applying to heavy vehicles. These include special limits for the overall size of vehicles, and additional limits on the distances between certain components of vehicles.

What If Someone Else Was Operating The Vehicle At The Time?

Where a dimension breach is detected, Roads and Maritime Services (RMS) can charge anyone in the chain of responsibility for the offence. In practice RMS often seeks to prosecute the operator of the vehicle. It does this by issuing the Court Attendance Notice to the person in whose name the vehicle is registered, i.e. the “registered operator”.

The registered operator of the vehicle may not have been the person operating the vehicle at the time of the offence. The law says that the operator of a vehicle is the person responsible for controlling or directing the operations of the vehicle. It is usually the person or company running the business in which the truck is used.

The registered operator may not have the necessary control of the vehicle to be classified as the actual operator, for example, if it is leased to another business.

If you were the registered operator, but not the actual operator of the vehicle, at the time of the offence, you must provide a statutory declaration to RMS nominating the actual operator within 14 days of receiving the Penalty Notice or Court Attendance Notice. If you do not do this, the law provides that you are “taken to be guilty” of the offence.

The information which must be contained in the statutory declaration is strictly prescribed by law. If you do not provide a complying statutory declaration in time the court can find you guilty of the offence.

The Reasonable Steps Defence

A “reasonable steps defence” is available to a person charged with a dimension breach offence if the person is:

  • the consignor;
  • the packer;
  • the loader;
  • the operator and the offence is a minor risk breach;
  • the driver and the offence is a minor risk breach.

To succeed in this defence you must satisfy the court that:

  • you did not know, and could not reasonably have been expected to have known, of the dimension breach; and
  • either:
    • you took all reasonable steps to prevent the contravention; or
    • there were no steps that you could reasonably be expected to have taken to prevent the contravention.

Although this defence seems straightforward, it is in practice quite technical to prove.

For advice or representation in any legal matter, please contact Armstrong Legal.

Michelle Makela

This article was written by Michelle Makela

Michelle has over 15 years experience in the legal industry, working across commercial litigation, criminal law, family law and estate planning.  Michelle has been involved in all practice areas of the firm and in her personal practice has had experience in litigation at all levels (State and Federal Industrial Tribunals, the Supreme Court, Court of Appeal, the Federal Court, Federal...

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