10/06/2026
Notice: “Factors Influencing Longitudinal Rail Movement Amplitude Derived from UAV-Based Measurements with Optimization-Based Geometric Correction” by Ramos, Dersch, Lima, and Edwards, published in the ASCE Journal of Infrastructure Systems.
This study developed a drone-based photogrammetric approach to quantify longitudinal rail movement amplitude near railroad structures (i.e., grade crossing, turnout, open deck bridge), and measure the effects of operational, geometric, and restraint-related conditions on it. The study analyzed 764 crossties near 20 structures across four U.S. heavy axle load freight corridors. A particular focus of the study was the role of rail anchoring in longitudinal restraint. Rather than simply classifying anchors as present or absent, or ETA or EOTA, the research characterized those components into Aligned (“A”), Embedded (“E”), Loose (”L”), and Absent (“0”).
Key findings of this research:
• Crossties with two aligned anchors (A-A) were associated with a 57% lower rail movement amplitude compared with non-anchored crossties (0-0).
• A crosstie with one loose anchor and one non-anchored side (L-0) was associated with an approximately 50% higher movement amplitude than the non-anchored reference condition.
• Directional traffic was associated with approximately 55% lower movement amplitude than bidirectional traffic.
• Grade was also statistically significant, with a one-percentage-point increase in grade associated with approximately 70% lower movement amplitude within the observed range.
This work demonstrates the potential of UAV-based measurements to investigate longitudinal rail movement in revenue-service conditions while providing additional insight into the role of effective rail anchoring. The results may help support future approaches to track inspection, maintenance prioritization, and assessment of longitudinal rail restraint.
đź”— Full paper: https://ascelibrary.org/doi/10.1061/JITSE4.ISENG-3044
Thank you to BNSF, Union Pacific Railroad, CSX Transportation, & Federal Railroad Administration.