Guest comment: Taking rail operations to a new level through quantum computing by David Hunt, Oliver Wyman

The next great leap in computing power is currently in progress. Known as quantum computing, it takes advantage of the special properties of subatomic particles to push computing power to almost unimaginable levels. For railroads, this could mean unprecedented levels of speed and flexibility in rail operations planning, helping to solve some of the industry’s most intransigent network problems, while also making rail networks safer and more sustainable.

The United Nations has proclaimed 2025 to be the “International Year of Quantum Science and Technology,” and leading-edge companies across industries are investigating and investing in quantum computing solutions. With the technology set to mature in a few years, they are identifying use cases that could propel them competitively and revolutionize their businesses.

The power of quantum computing

Currently, most of the world uses “classical” computers that rely on billions of electrically powered transistors (“on/off switches”) spaced only atoms apart on silicon chips. But the ability to increase the computing power of classical computers is slowing. Quantum computers are the next step, as they rely instead on subatomic particles to process information at much higher speeds. How much faster exactly? Where a classical computer might take a thousand years to solve an extremely difficult problem, a quantum computer can solve that same problem in seconds.

Although the possibilities of quantum computing have been known for decades, only recently has the technology begun to catch up. Companies such as IBM, D-Wave and IonQ are leading the development of commercial quantum computer hardware, and technology giants such as Amazon, Google and Microsoft are making substantial investments, as well.

The most promising use for quantum computers is in optimizing large-scale systems and running extremely large simulations — tasks that classical computers struggle to do today. For example, quantum computer-based simulations are being developed to better understand chemical reactions, leading to improved battery life and more efficient hydrogen fuel cells. Quantum computers also could facilitate the training of larger AI systems, leading to more powerful task automation.

Leveraging the massive power of quantum computers is expected to lead to a range of advances for railroads. Most critically, railroads are being continuously challenged to increase their performance to compete more effectively with trucks and win back market share. Transit reliability and speed however are hampered by the sheer complexity of rail network operations — something that quantum computing could cut through in a way no current information technology system can.

Quantum computers could improve route planning and scheduling by quickly solving much larger, more complex optimization models, revolutionizing the time it takes now for route planning and scheduling. And because quantum computers can process vast amounts of real-time data in real time, they could be used to predict traffic patterns much more accurately to optimize flow, thus reducing network congestion and delays.

One early application for quantum computing in rail could involve combining the strengths of classical and quantum computers to optimize large dispatching problems. Classical computing would be used to initialize the problem on the front end and process the results on the back end; quantum computing would be used to swiftly search through a vast array of potential solutions to determine optimal schedules that minimize delays.

Quantum computing also has the potential to help railroads and rail OEMs rapidly upgrade technology to realize:

• rapid development of sustainable solutions, including more efficient batteries, hydrogen fuel cells and other clean fuel sources;
• advanced material design, such as lighter and stronger components that are less susceptible to failure;
• increased safety through the use of quantum-based sensors, which are orders of magnitude more sensitive than existing sensors, to better detect and predict mechanical failures; and
• upgraded cybersecurity, including enhanced encryption methods, better protecting against cyber threats.

Early days but not for long

Deutsche Bahn and European rail researchers have begun looking at how quantum computing can solve problems such as reoptimizing train tables in the event of delays and conflict management on single-track lines. To date, the focus has been on developing new quantum algorithms (think: step-by-step instructions) to solve small problems, then validating solutions against existing algorithms on classical computers. These quantum algorithms will then be ready for real-world commercial application as the hardware continues to advance. It will be important for railroads to stay up to date on this game-changing technology, so that they are ready and able to leverage its enormous power.

David Hunt is vice president of Oliver Wyman and 2025 president of the Institute for Operations Research and the Management Sciences.