Description
Remove Overlapping Centerlines uses the topological operations Intersect and Simplify together, which can cause very small polyline segments of a length around and above the feature class tolerance to be destroyed. Associated route shapes may change slightly beyond tolerance as a result of using this tool.
Solution
Consider using the Repair Geometry and Integrate tools on your data so that future topological operations do not produce small slivers. Make sure to execute these on temporary backups or versions of your data so that you can roll back the changes, if necessary.