At WikiMotors, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is a Road Train?

A road train is a trucking marvel, linking multiple trailers together like a metal serpent to transport vast quantities of goods across expansive terrains. These behemoths of the highway maximize efficiency and redefine long-haul delivery. Imagine the power and coordination it takes to navigate such a giant—what innovations make this possible? Join us to explore the mechanics behind these impressive convoys.
Lori Kilchermann
Lori Kilchermann

A road train is a specially-equipped semi-tractor and trailer rig used in Mexico, Argentina, America and Canada, but it is most common in Australia. Typically consisting of a very powerful tractor pulling four full-sized trailers, the road train is considered to be one of the largest wheeled vehicles in the world. Some of the largest road train vehicles operate solely on private land instead of public roads; therefore, weight and length restrictions do not apply. While fuel tankers represent the majority of road train vehicles, there is nearly every type of trailer imaginable in use with the behemoths today.

The earliest configuration for a road train was that of a military truck hauling two or three trailers. These vehicles were not very dependable due to their age. Drivers of these vehicles were often subjected to harsh conditions, as the vehicles had open cabs. The Australian government had commissioned several self-tracking trailers to be built to aid in the maneuverability of the road train. The self-tracking trailer had steerable wheels at each end to aid in maneuvering on the winding roads found in the Australian Outback.

Woman with hand on her hip
Woman with hand on her hip

An Australian cattle hauler is credited with the design of the modern road train. Using a surplus United States military truck and several of the self-tracking trailers as prototypes, he built a road train that could haul over 100 bulls 200 miles (320 km) from southern Australia to Northern Australia. Local trailer manufacturers soon began to copy the new trailer design and began producing the self-tracking trailers for several customers. Popular semi manufacturers began producing specially built units, with Kenworth and Mack becoming two of the more preferred models.

While the common units utilize three or four trailers, some of the longer trains will haul up to six trailers at a time. These super trucks are known as Powertrain units. The larger trains use an engine mounted in the back of the rear-most trailer to aid the train in moving. Without the assistance of the rear engine pushing the train from behind, the tractor could break a drive shaft or pull a hitch loose from one of the trailers. The rear engine is operated via remote control from the cab of the road train.

The world's record for the longest train has switched hands a number of times since the 1970s. The record is 112 trailers pulled by a single truck. The record-breaking truck was 4,836 feet, 11 inches (1,474.3 meters) long and was pulled a distance of 328 feet (100 meters).

You might also Like

Discussion Comments


Do you need special certifications and training to get road train jobs? Its seems like this is a step above your average trucker.


The article talks about North American road trains and Australian road trains but I am wondering if they use these in other parts of the world. Why wouldn't they be useful in Europe, Asia and Africa. They need cargo moved as much as we do.


That record at the end seems impossible to me. How could any truck haul all of that weight?

I used to be a trucker myself and I have seen how much even one trailer can effect the performance of a truck. Having 111 more linked behind you seems like a miracle.

But I am all for it in principle. The more cargo you haul the more money you make as an operator. If truck drivers can haul more stuff in a single haul they might be able to make a wage that is actually worth it. That's why I ended up out of the industry, I just couldn't make enough money.


Wow, I have never heard of or seen a road train before. I know that it is now pretty common to see tractors hauling two trailers behind them but four trailers seem outrageous.

I'm surprised that they can manage this. There was a lot of controversy when trucking companies began to increase loads and attach additional trailers to tractors. They argued that they were saving fuel and promoting efficiency by linking more cargo to each truck. The opponents argued that these super trucks presented a major safety hazard and would lead to more violent and catastrophic wrecks in the future.

Having a truck haul four trailers would only increase the danger to other drivers on the road. I am all for conservation but we have to be realistic about causes and effects. Having a fleet of super trucks will only lead to super accidents.

Post your comments
Forgot password?
    • Woman with hand on her hip
      Woman with hand on her hip