What Is Intermodal Transportation? History, Benefits, Examples

What Is Intermodal Transportation? History, Benefits, Examples

Intermodal transportation is not as mysterious or complicated as the name would have it sound. It means transporting one set of goods in a steel container using two or more modes of transportation, such as rail and truck.

Intermodal transportation is not as mysterious or complicated as the name would have it sound. The intermodal definition is transporting one set of goods in a steel container using two or more modes of transportation, such as rail and truck. An intermodal carrier using rail or truck is not the only means of transit that intermodal utilizes. 

Intermodal falls into four general categories: Truck, rail, sea, and air. 

Trucks can easily transport steel freight containers. They are usually the first mode of transportation that intermodal shipping relies on and uses to get the process underway. 

Additionally, trucks are typically the last mode of transportation to handle the freight on the way to its final delivery. 

Trains are an even more gainful means of transportation within intermodal transportation. Trains can transport hundreds of steel containers across thousands of miles with low transportation costs. 

But air and sea are the only modes with the potential to move freight containers between continents and across bodies of water.

Intermodal transportation has a growing list of benefits, including speeding free trade, lowering costs for consumers and economies, and reducing carbon dioxide impact on the environment compared to other transportation means.

Despite its upsides, intermodal transportation does also have some setbacks that draw some shippers to other transportation solutions. 

Sometimes intermodal transportation delivery times can be less than reliable, as weather can affect all transport means. Additionally, though it can reach far, intermodal is not the ideal solution for some rural parts of the United States or other countries. Additionally, it cannot avoid using fossil fuel at some stages of transportation, which is a disadvantage due to current high energy costs.  

Though its transportation modes are not new, the practice of intermodal transportation is. Before the 1960s, trains and ships did most of the shipping in the United States and internationally. 

The development of new vehicles with new capabilities changed freight transportation in that decade. Intermodal transport has gone on through the next 60 years to continue improving, becoming more efficient, and introducing more possibilities for freight delivery. 

To see more of the effect, benefits, drawbacks, and history of intermodal transportation, keep reading, as this article will detail it. 

What Is Intermodal Transportation?

Intermodal transportation starts before shipping begins, especially as intermodal providers begin planning, loading, and determining the type of intermodal shipping process needed.

Logistics companies and intermodal shippers alike use two broader categories of intermodal freight. 

Shippers decide between domestic and international intermodal transportation depending on the shipment. Domestic is what it sounds like: shipment within a country, province, or region.

For domestic transportation, most shipping services will use the railroad for reduced costs or over-the-road truck transportation to get cargo to customers for a reduced price. If the receiver needs the items faster, the intermodal service will use other modes of intermodal shipping.

Typically aircraft can get cargo delivered faster than over-the-road services and fulfill overnight or next-day deliveries. Aircraft are used in domestic shipping in large countries when the supply chain may be too long because it stretches across the entire country.

Air transport is included in international intermodal transportation, especially if cargo needs to move between countries quickly. 

Air transportation is typically reserved for small cargoes in international intermodal transportation, as planes are limited in the weight they can carry. But nothing can compete with their speed, and thus they are used for urgent cargo. 

More typically, for less urgent cargo in international intermodal transportation, a truck or train will get the cargo from its origin to a port. The freight will proceed onto a barge or a large freighter. 

This ship will then take the cargo to another port, where a train will likely transport it to a destination where a truck can take over and get it to the final destination. 

But before this process can even begin, intermodal transportation has to undergo containerization.

Containerization is packing the cargo into standard-sized steel containers equipped to hold it without damage. Intermodal containers are large steel containers that look like train cars but do not have wheels. 

Loaders pack the cargo so its weight can distribute evenly across the container’s floor. This keeps the container stable in transit and keeps its contents from spilling out. 

Usually, the intermodal transportation process itself begins by taking these loaded containers and putting them onto chassis so a freight truck can carry them.

History of Intermodal Transportation

Before intermodal freight transportation, shipping cargo involved a heavy labor cost in a process called “break bulk cargo.” Logistics companies and shippers shipped cargo by packing it by hand in small packages into ships, trucks, and trains. 

With no intermodal container to package the items and with none of the various modes of transit having reliable capacity, the packages had to be loaded and unloaded one by one at each transfer during the entire transit process. 

Packages were constantly lost. It did not matter how fast the rail traveled or how efficient the supply chains were; this process was not cost-effective and seriously slowed transportation. This constant slow loading and unloading even composed the majority of transportation costs.

That is until logistics companies began applying logic used by both the United States Military and by English rail car owners to create containers that would reduce transportation costs and increase the capability of intermodal shipping.

Development of Containers

The innovators who gave us intermodal freight took container processes already in place and refined them. In late 19th century England, rail companies used large containers to move luggage from trains to ships. 

freight containers

English companies also used rail and ships together to ship coal in large containers, marking perhaps the first historical use of intermodal transport.

The United States Navy took this forward by developing steel containers during the Second World War to transport ammunition and supplies. By the 1950s, logistics companies started designing bigger steel containers to keep cargo in the same container as it traveled by rail, truck, or ship.

The 1960s: Intermodal Shipping Becomes Popular on the Seas

We will discuss containers further and why they are crucial to intermodal freight shipping. For now, we will mention this part of their history: as containers developed over the late 1950s, they became standardized. By making their standard size 8 feet and 6 inches, steel containers had a reliable capacity that shippers could anticipate.

Intermodal transport quickly became more feasible and popular with the rail industry and many logistics companies for its potential to significantly reduce costs. There was no more unloading and reloading onto the next ship or the next step in the supply chain. Instead, you only had to move the container to the new mode of transportation.

This phenomenon coincided with the ongoing development of container ships specifically outfitted for more efficient shipping. In 1931, the first container ship made its debut, but it had yet to meet the standardization of future intermodal and multimodal transportation. In the 1950s, United States shippers started using old oil tankers from the Second World War in tandem with the development of containerization.

By the 1960s, container ships and standard-size containers made international bulk shipping more efficient. This efficiency meant railroads like Union Pacific could reach even more people via rail. 

The possibilities of intermodal transport increased exponentially when the regional manufacturing facility and hub became a fixture in the supply chain. These institutions, linked to the rail yard at a specific point on the route, allowed freight to transfer between different modes and allowed trucks to add more cargo along a shipping route while removing congestion from seaports or larger ports.

With these combined developments, intermodal transport became the premier means of transit for freight on the seas and railroad tracks by the late 1960s.

The 1980s: Further Development of Rail Intermodal Freight Transportation

Intermodal transportation processes and containers improved over two decades. However, the innovators in charge of the transport still thought something was lacking in efficiency, and it was possible to ship more freight at lower costs. In 1977, intermodal transport innovator Malcom McLean started encouraging the use of “double stack cars” on rail lines.

While they did not become standard until 1984, these cars are now standard in intermodal transport.

The key difference between normal rail cars and double stack cars for intermodal transport is easy to see. Double stacks carry two stacks of intermodal containers in a “well” car, as opposed to a flat car, which lowers the height of the containers and concentrates the center of gravity more safely.

This development significantly increased the efficiency of intermodal transport exponentially by enabling intermodal shipments to carry more cargo and avoid highway congestion entirely. Due to this development, final delivery sped up, and rail transportation became a particularly efficient means of cargo transit.

Today: Development of Intermodal Freight Shipping Ramps

As intermodal transport continued to progress and containers continued to improve, there was still one glaring problem interfering with the entire progress of this phenomenon: the underdeveloped intermodal ramp system and the lack of technology for proper data analysis regarding freight transportation.

Ramps in the earlier days of intermodal transport were called “circus style” ramps, and they were less efficient than current ramps because they required trucks to pull containers down, and they could not move containers using cranes as they started doing in the 1980s. This improvement in intermodal setup made it easier to remove containers from trains and move them between two or more modes of transport.

helicopter flying

Then: Tracking and Inventory

But even in the 1980s, technology still was not equipped to trace intermodal transport and give customers, moving companies, or partners accurate delivery times. Companies used paper and pen and kept a paper trail to keep track of massive loads of cargo. This inefficient means of keeping track of cargo and confirming arrivals at ramps meant that inventory costs could still be high, and there would have to be a change.

Today: Tracking and Inventory

That change came with the enhanced development of shipping software in the first two decades of the 21st century, which used the internet and enhanced computer systems also to foster lower costs for inventory and information tracking. 

Now, when a container arrives at a ramp, it is easy to enter into a shared system between companies. Based on location and means of transport, shippers can now provide an accurate estimate of when a container will arrive at its final destination.

Companies and intermodal transportation analysts can also use the data from these information systems to track arrival time and fuel efficiency, and even estimate carbon footprint.


Containerization is the most important milestone in the history of intermodal transport. Without the development of standard containers, today’s multimodal or intermodal transportation for cargo would not have emerged.

The Start of Containerization

We briefly mentioned the beginning of containerization by discussing England’s coal containers, but now we can go into more detail. In the 19th century, coal companies used large timber boxes to begin transporting coal between modes of transport. 

As this started to profit several companies and improve the industry’s efficiency because it did not require the complicated sorting that break bulk shipping needed, companies tried to emulate this first means of intermodal transport.

Some companies even started employing stronger metal containers to use in multimodal transportation, while in Poland, the first attempt at standardizing containers came to life.

But the First and Second World Wars both got in the way of furthering the development of containerization. Thus it was put on hold until after World War II.

Containerization after World War II: The Start of Standardization

The United States began using standard-size steel containers to transport supplies and weapons during the Second World War on oil tankers that would later become container ships.

But these were not the standard-size “ISO containers” we see today. They were smaller and yet to be internationally standardized according to certain quality and size customs. They were also different sizes than the containers other countries were using.

In the 1950s, Europe began trying to create standard containers to use for shipping around the continent and saw some success. Still, intermodal transport became possible in 1955 when the first intermodal container appeared on the scene, developed by Malcom McLean and Keith Tantlinger.

These first intermodal containers were 8 ft x 8 ft x 10 ft and had a locking mechanism at their corners so they could stack high, and cranes could easily lift them. After McLean used a retired oil tanker to ship containers from New Jersey to Houston to prove the efficiency of this system, this container size became the de facto of intermodal transport for a long time.

Intermodal Containers in the 1950s and 1960s

The US government began using the 8 x 8 x 10 box to ship supplies to Vietnam, but within the United States, several companies were using different sizes of containers. While it meant intermodal transport could still develop, it meant there was no standardization, and the capacities of containers were wildly different.

Many companies used 24-foot long containers, others used 35-foot long containers, and others even tried to develop bigger containers.

Without any standardization, there was no way to rely on the capacity of the container itself, and shipping became a guessing game according to the company you partnered with.

Additionally, cranes, trucks, and other equipment could not always accommodate the different containers. Thus, international shipping companies, the railroad companies of the United States and many European countries, and trucking companies met to standardize containers in the late 1960s.

Standardized Containers: ISO

The International Standardization Organization came up with the dimensions and standards that transport containers must meet today. Containers must meet these standards so they can be used in shipping, and once they do, they become certified “ISO containers.”

Container Sizes and Weights

The five standard container sizes used today are as follows:

  • the 20-foot long unit
  • the 40-foot long unit
  • the 45-foot long unit
  • the 48-foot long unit
  • the 53-foot long unit

All containers are generally 8’6″ high and wide. The ISO’s capacity term for the volume of these containers is the TEU – the “twenty-foot equivalent unit” – and it measures how much cargo can fit inside the container.

All sizes can hold a maximum of 36,000 kg, including the weight of the container itself.

Container Markings

All shipping containers approved by the ISO must have several codes marked on their outside that indicate the manufacturer, the port of origin, its owner, and its use. With such markings, each person managing the steps in the entire progress of the shipping process can register the information and help others track the containers if needed.

Other Standardization

Containers include corner locks developed in the 1950s to make moving them easier. Though the ISO does not standardize any method of securing steel container cargo, the standard sizes of the containers allow the shipping or moving companies who use them to secure them and secure the cargo inside with measured straps and lashing.

Modes of Transportation

Though there are four standard methods of intermodal transport, they differ greatly among the countries that use this method of cargo transport.

Rail intermodal

Rail transport is the shipment of masses of packages in containers using pre-existing railroad tracks to shuttle cargo between destinations. It is often used to get items between distant ports quickly, but it can also be used to get cargo from one hub to the other, where cranes can transfer the loads to truck-based transportation.

In 2020, there were 10,800 billion tonne-kilometers of train freight traffic.

At the moment, rail intermodal generally uses the standard 20-foot long containers, though there are other cases where it uses the other four containers to ship greater volume. Rail is used more in Asia than it is in other markets, though it boasts strong performance in the United States.

The ability to contain twice the load with double stack well cars and the rail and truck network offered by companies like Hub Group and Union Pacific means the United States can ship efficiently overland via rail and avoid delays due to traffic and congestion.

Within the European Union, countries are currently trying to push for greater use of rail transport to reduce carbon footprint, as trucks at the moment are their main means of land transport.

Train transport in Europe, such as in the UK, does not use double-stack well cars and instead uses flat cars that can fit one layer of 20-foot containers, so they cannot ship to the capacity American shipping companies can.

Container Ship

Shipping by ship is the most versatile of the intermodal methods. Ships transfer freight on rivers, canals, seas, and oceans and can move freight between major ports both domestically and internationally.

In 2020, 1.85 billion metric tons of freight reached their destination through at least a partial journey on a container ship. This number shows that container ships account for a significant portion of the world’s shipping.

In the United States, container ships operate on the Mississippi River and the coasts, often moving especially between the west coast, China, and Japan to move freight between the three countries. On the east coast, freight also moves to the Gulf of Mexico from Northern ports.

Within the European Union, ships account for much of the intermodal transportation traffic, especially on the Danube and Rhine rivers, which can accommodate shipping between several countries and even foster the transfer of freight between ships as they lead to the North and Black Seas.

Unlike rail, ships use two general sizes of containers for shipping due to their high capacity: the 20-foot long container and the 40-foot long container.


Aircraft is the fastest-developing of the intermodal transportation methods but remains the most limited for actually fitting containers. While we have no exact specifics on its capacity within intermodal transportation, we know air freight grew another seven percent in the last year.

The American market uses this option for urgent freight but often uses smaller containers that are not ISO containers to ship items in the “bellies” of passenger planes, and Europe does the same. If not engaging in this practice, they will often use smaller freight containers that do fit in planes.

Boeing, however, patented a plane five years ago that can fit the 20-foot intermodal container, and other companies have responded by attempting to do the same, so we can expect to see this sector develop further.


Trucking is the simplest to understand of the intermodal transportation sectors, but it is the most susceptible to inefficiency. Trucks can typically only transport one container, but they can accommodate all sizes of containers. Trucks transport packages and items overland on highways, roads, and streets.

As mentioned before, they are usually the first and last transport methods used on a container’s journey.

10.23 billion tons of freight were moved by truck alone in the United States in 2020. The United States is not alone in trucking being a massive shipping sector either. Several companies facilitate this massive volume of transport, such as the Hub group.

Europe shipped over a trillion tons of freight in 2021, even when the sector declined last year, which means trucking is the most used means of intermodal transportation in this continent.

Benefits of Intermodal Transportation

Now that we’ve outlined how to define intermodal and how Intermodal transportation works, let’s take a deeper look at its benefits.

Reduced Cost

There is no need for longshoremen to sort the packages within the containers or unload and reload the freight, which adds costs and time.

Potential to Mitigate Climate Change

When intermodal transportation works efficiently, it fosters fuel efficiency. It limits environmental damage because the fuel is used to transport far more weight than it would otherwise be able with a single transportation method.

Thus, its carbon footprint is lower than many other means of shipping.


With standard marked containers and improved technology, it is far easier to estimate arrival dates, track containers, analyze the movement of freight, and see how to speed it up.

Increased Capacity

Intermodal transportation can ship massive loads of items and containers safely and reliably,

Disadvantages of Intermodal Transportation

Like everything, however, intermodal transportation has its disadvantages. These are the major of them.

Susceptibility to Weather

All methods of transportation in intermodal shipping have the potential to be slowed down by rain, storms, and otherwise dangerous conditions. Ships are particularly vulnerable to environmental hazards, as sudden storms cannot only stop them from sailing but indeed knock the freight off of them into the water.

Disease Vector

Since most ISO containers are not temperature regulated, many contain pests that will sneak out of the containers and spread diseases at new ports. These containers also have the potential to ferry invasive species between ecosystems.

Risk for Damage

Since the freight is handled quickly and generally not opened, there is a risk of damage that no one will even see as the process moves. The more freight changes hands as it moves, the more this risk increases.

Intermodal Transportation Example

As an example of the relatively simple process that intermodal transportation can follow, we will outline here an international intermodal shipping situation, as it utilizes and demonstrates the domestic shipping network.

International intermodal shipping:

  • Your freight needs to get from Chicago, Illinois, to Shanghai, China and is too large to fly.
  • Step A: You commission a company or companies to complete your shipping for you.
  • Step B: Your freight is containerized into ISO containers.
  • Step C: Hub group, the company you commissioned to transport your freight on its first leg, loads it onto trucks and brings it to Chicago’s train hub, where a shipping company takes them on trains that travel to the Port of Los Angeles.
  • Step D: Once in Los Angeles, cranes will load the containers onto ships.
  • Step E: The ship you contract will bring the containers, along with many others, to Shanghai, China.

What Is the Environmental Impact of Intermodal Transportation?

Due to its fuel efficiency, reliance on reusable materials, and reduced use of trucks in the process to avoid traffic and fuel waste, intermodal transportation is a sustainable means of shipping.

Intermodal vs. Multimodal Transportation

Intermodal transportation and multimodal transportation have one real difference, and it is regarding how contracts and planning work. Both are under the umbrella of “intermodal,” but with standard intermodal transportation, you must contract and plan each separate step.

Multimodal transportation has a single contract system – you make a contract with one company that will organize the intermodal transportation.

Intermodal vs. Transloading

The difference between intermodal shipping and transloading is easy to understand. Intermodal shipping moves entire steel containers without sorting through the contents inside them. Transloading means unloading the container and sorting through it to put the freight on different transportation methods so they can head to their final destination.