Hi Sean,
The issue arises due to the alignment of the Segments. Switching to Automatic X Alignment should resolve it. Additionally, we typically advise against applying modifiers directly to RailClone objects, as this disables instancing. While this might not significantly impact performance in most cases, it's important to note that the entire RailClone object will be treated as a single mesh. Instead of using the UVW Map modifier, consider using the Apply Box Mapping feature.
Please find attached the modified version of your scene (240828_RC_Edging_ITOOSOFT.max). I hope this helps.
Best regards,