I can deal with bad geometry by using the Geoprocessing Editing tools. For example I can deal with overshoots and undershoots with the Snap tool. A snap tolerance can be set (ex. 3 feet) and any lines within the tolerance of an intersecting line can be snapped. My CAD to GIS conversion script makes use of the snap tools to ensure that all centerlines snap. Download and check out how they are used.
Eric J. Rodenberg | Solution Engineer Transportation Practice
Esri | 7775 Walton Pkwy, Suite 270 | New Albany, Ohio 43054-8202 | USA
T 614-933-8698, ext. 5503 | erodenberg@esri.com | esri.com