The Feature Class to Feature Class tool and the Feature Class to Geodatabase scripts, in the Conversion toolbox, allow you to migrate route data from any supported format into a geodatabase. The conversion preserves all measure values. You can also copy feature datasets and feature classes to a geodatabase using Copy.
When migrating to a geodatabase, you can create a stand-alone feature class, a feature class in a new feature dataset, or a feature class in an existing dataset.
When creating or importing a feature class, you can specify the coordinate system, spatial domain, and resolution in the environment settings. Set the spatial domain and resolution carefully, because once you have created the feature class, its attributes cannot be changed. The default for the m-tolerance, m-resolution, and m-domain are appropriate for most users.
If you are creating a feature class in an existing feature dataset, the new feature class will automatically have the same coordinate system, spatial domain, and resolution as the feature dataset. In this case, there is no need to specify the spatial reference parameters in the environment settings before you import. The exception is the m-tolerance, m-resolution, and m-domain, which can be different for each route feature class. When migrating to an existing feature dataset, it is advisable to ensure the default m settings (tolerance, resolution, and domain) are appropriate for your data.