The ultimate guide to heavy vehicles

What is a heavy vehicle?

A heavy vehicle, as defined in the Heavy Vehicle National Law (HVNL), is “a vehicle that has a Gross Vehicle Mass (GVM*) or Aggregate Trailer Mass (ATM**) of more than 4.5 tonnes”.

* The GVM of a vehicle is, according to the National Heavy Vehicle Regulator (NHVR), is “the maximum it can weigh when fully loaded, as specified by the manufacturer”.

** ATM weight is “the maximum towing weight of the trailer/caravan as specified by the manufacturer”, according to CarsGuide’s comprehensive yarn on vehicle weights explained.

[read-more-default-title]

You see plenty of them on the roads going about daily business but to understand what a heavy duty truck is, you first have to appreciate how heavy the average car is.

For reference, the average weight of a car is 2.05 tonnes. That figure comes from averaging the weight of popular vehicle types spanning the Australian new car market.

The average weight of a small/compact SUV is about 1380kg, the average weight of a medium SUV is around 1630kg, the average weight of a large SUV is approximately 2000kg.

Then, the average weight of an upper large SUV is about 2580kg, the average weight of a ute is around 2140kg and the average weight of a US pick-up is approximately 2600kg.

The average weight of a car is 2.05t (Image: Mike Bird)

According to the NHVR, what is classified as a heavy vehicle includes semi-trailers, B-double freight trucks, road trains, passenger buses, vehicle carriers, livestock and other agricultural vehicles, mobile cranes and other special-purpose vehicles.

So, what does heavy mean in vehicles? Well, according to that aforementioned authority, the heavy vehicle definition is any vehicle with a GVM or ATM of more than 4500kg.

People often use terms such as heavy rigid vehicle, heavy commercial vehicle and heavy transport as interchangeable ways to refer to what is a regulated heavy vehicle, but what is classified as a heavy vehicle fits the aforementioned NHVR definition.

The HVNL regulates the use of heavy vehicles that have a GVM of more than 4.5 tonnes. That law applies nationally, except for the Northern Territory and Western Australia.

There are some 25 combinations of the D-Max ute.

If a vehicle is classified as heavy, and it is used commercially, the NHVR states that “Everyone who works with heavy vehicles – from the business that employs a driver or owns a vehicle, to the business that sends or receives goods – is accountable for the safety of the heavy vehicle, its driver, and its load throughout the journey”.

So, while heavy vehicle definitions may differ slightly there’s generally a consistency.

What is a heavy vehicle in NSW? Transport for NSW states, “A heavy vehicle is defined as a motor vehicle or trailer that has a Gross Vehicle Mass greater than 4.5 tonnes.”

What is a heavy vehicle in Victoria? VicRoads says, “To drive a truck or bus with a Gross Vehicle Mass greater than 4.5 tonnes or a bus which seats more than 12 adults you will need a Victorian heavy vehicle licence.”

Some heavy vehicles have restricted travel conditions. (Image: Richard Berry)

There is a NHVR Chain of Responsibility (CoR) that must be followed in the general use of a heavy vehicle, and the CoR operates in principle as any workplace health and safety laws do.

National heavy vehicle driver fatigue laws apply to fatigue-regulated heavy vehicles, which, according to the NHVR, are “a vehicle with a Gross Vehicle Mass (GVM) of over 12t; a combination when the total of the GVM is over 12t; buses with a GVM over 4.5t fitted to carry more than 12 adults (including the driver); a truck, or a combination including a truck, with a GVM of over 12t with a machine or implement attached”.

Some heavy vehicles have restricted travel conditions, must use approved road networks, and may be restricted from accessing certain roads and streets during certain hours of the day.

There is some uniformity to regulations across the country and it’s improving but it does differ slightly from state to state so check with the appropriate authorities before you go trucking into another state or territory.

(Image by Ivan from Pexels)

The Northern Territory and Western Australia remain outliers to consistent nationwide laws in some regards though, with their own take on a few regulations, such as fatigue management, due to the long distances between towns and the geography of those regions, among other reasons. Fair call.