Almost half of all container trucks in Sweden are being driven without a load. Researchers at Chalmers University of Technology in Sweden, have developed calculation models that give a detailed picture of the journeys – and therefore provide guidance for more efficient container transport, with lower costs and reduced emissions.

In 2019, the global transport sector accounted for around 15 per cent of the world's greenhouse gas emissions, and road traffic was the largest source of emissions in the sector*. An important part of reducing emissions is to make freight transport more efficient. Containers play a central role in world trade, as they can be moved between ships, trains and trucks. However, after unloading, there is not always new cargo nearby, which means that the container must be moved before it can be used again.

Researchers at Chalmers University of Technology have analysed Swedish freight traffic between 2016 and 2019, and conclude that almost half, 44 – 46 per cent, of all truck transports with containers took place without a load. In total, the empty trips accounted for about a third of the total mileage of freight traffic.

"A large part of the container transports do not carry any goods, but still take up road capacity and require fuel, infrastructure and working hours. This means costs and emissions that we want to avoid," says Violeta Roso, Associate Professor at Chalmers.

Geography is more important than industry

The empty transports were unevenly distributed. About 77 per cent took place within the same region; and the start and end destinations had a greater impact on the probability of an empty trip than which industry they belonged to. In Blekinge, Västra Götaland, Skåne and Kalmar counties, container journeys were less likely to be empty when starting in these regions, but more likely to be empty when ending there. All four counties have major ports where imports exceed exports.

"Empty transports were also significantly shorter than those with cargo. This indicates that trucks are often redirected to limit the distance with empty containers," says Iván Sánchez-Díaz, Associate Professor at Chalmers.

More accurate measures can reduce empty transports

The researchers' models take into account the differences between geographical location and the types of industry the container trucks work for, and thus show where measures can have the greatest effect.

"The models show which origins, destinations and sectors have the highest probability of empty container trips. This makes it possible to target efforts more precisely, for example towards port regions, or certain industries," says Violeta Roso.

According to the study, better coordination and information sharing can reduce the need to move empty containers. The researchers make several suggestions towards the industry, such as that hauliers can work more with the planning of return loads or that shipping companies to a greater extent share information about available containers and where they are needed.

Empty container transports are a global challenge. According to the researchers, the method can be implemented in more countries, to quantify empty containers movements and understand the key factors explaining them.

"We hope that the research will help the transport industry to see where there are the greatest opportunities to reduce unnecessary driving, and contribute to authorities or key stakeholders being able to coordinate their transports better. It can be another step towards reducing the transport sector's climate impact, not only in Sweden but also internationally," says Violeta Roso.

* Source: IPCC (2022), Climate Change 2022: Mitigation of Climate Change, Working Group III.

Read a longer news story about the study at www.chalmers.se/en/. The text may be used in its entirety.
More about the research

The scientific article Containerized Truck Movements in Sweden Payload and Empty Trip Modeling has been published in the Transportation Journal.
The authors are Violeta Roso, Iván Sánchez-Díaz, Juan Pablo Castrellon and Lokesh Kumar Kalahasthi. At the time of publication the researchers were active at Chalmers University of Technology, Sweden and the Indian Institute of Technology (IIT) Tirupati, India.

The study is based on data from Swedish truck transports collected by Transport Analysis during the years 2016–2019. The researchers used statistical models to estimate both load weights and the probability that a container transport takes place without a load.

The research project was funded by the Swedish Energy Agency within the project TOMPOS, Increased Transport Efficiency Through Reduced Empty Positioning of Containers.

More about the results: How empty container shipments can be reduced

• Hauliers can improve the planning of return loads.
• Shipping companies can share more information about available containers and where they are needed.
• Freight owners and freight forwarders can coordinate export shipments with available containers.
• Ports and terminals can improve the storage, groupage and replacement of empty containers.
• Public actors can support common data standards and digital platforms that facilitate coordination.

More about barriers to return loads:

It is not always possible to match empty containers with return cargo. Goods may be missing in the right place or at the right time, and the container may be of the wrong size, condition, or equipment. Ownership and contract terms can also prevent other actors from using it.
In addition, hauliers, freight forwarders, shipping companies, ports, terminals and freight owners often plan transports separately. Information about containers, goods, times and agreements is not always shared. Empty relocation is therefore not only a transport problem, but also a question of organisation and coordination.
Source: The article Assessing the eco-efficiency benefits of empty container repositioning strategies via dry ports, published in the journal Transportation Research Part D: Transport and Environment.