How must a defective rail be marked in track according to the FRA?

A defective rail must be marked with a highly visible marking on both sides to ensure that it stands out and can be easily identified by workers and operators in the area. This practice is essential for safety, as it enables individuals to quickly recognize a potential hazard and take necessary precautions. The requirement for marking on both sides further enhances visibility from different angles, ensuring that those passing by or inspecting the rails can see the markings no matter their approach direction. This method of marking is standardized in the FRA regulations to maintain consistency and safety across the rail industry.

Other methods, such as using stickers, paint, or colored flags, may not provide the same level of visibility or permanence required in a rail environment, which is why they do not meet the FRA's specific guidelines for marking defective rails.