Researcher keeps trains safe with high-tech railroad monitoring

As freight and passenger trains traverse thousands of miles of railroad track in the U.S. every day, just one damaged or malfunctioning track segment can cause slowdowns, if not catastrophes. Visual inspections keep the tracks in line, but it’s a labor-intensive process that offers limited information — and can be subject to human error.

Deb Mishra, associate professor in civil and environmental engineering, hopes to change all that. His research focuses on instrumenting railroad tracks with state-of-the-art fiber optic sensors that continuously measure how track structures respond under real train loading, especially in track transition zones, where changes in stiffness can accelerate deterioration and increase maintenance costs.  

By using optical fiber sensing, or technology built on light, to “listen” to the rails, Mishra is helping move railroad inspection from periodic checks to continuous, data-driven monitoring, ultimately supporting safer, more resilient rail infrastructure for the future. 

"The goal is continuous, real-time monitoring of track conditions," said Mishra. "Operators could instantly see if a section is ‘green,’ ‘yellow,’ or ‘red,’ helping prevent derailments and enabling proactive, cost-effective maintenance."

How it works

Mishra uses two kinds of light-based sensing technologies that are durable, precise, and suited for harsh railroad environments: 

• Fiber Bragg Grating sensors measure rail strain with high accuracy.
• Distributed acoustic sensing systems capture dynamic track response over long distances. 

Mishra’s team tested early versions of the system in the lab. Next, they created a detailed computer model of a full-sized railroad track, verified that it matched the lab results, and used it to predict how the system would perform in real-world conditions.

Finally, they took the system to the Transportation Technology Center in Pueblo, Colorado, a large railroad testing facility run by the U.S. Department of Transportation, to evaluate its performance in the field. 

What they found

When the team put the sensors to the test, the results were clear. As trains applied different levels of force, the fiber-optic sensors captured the rails’ response with remarkable precision. What they found matched what long-trusted instruments had been measuring for years, showing that light-based sensors can stand up to the high-stress world of railroad tracks and deliver dependable, real-world insight. 

Expanding railroad track research at Virginia Tech

Mishra’s research began when he was at Oklahoma State University but continues at Virginia Tech, where he is expanding his work in railroad track instrumentation. He is currently establishing a track structure research laboratory and will teach Introduction to Railroad Engineering as a civil and environmental engineering elective in upcoming semesters. 

Mishra’s work is supported by the Federal Railroad Administration and includes partnerships with the U.S. Army Corps of Engineers, ENSCO Inc., the Association of American Railroads, LUNA Innovations, and AP Sensing.