How To: Convert coverage route features to polylineM shapefile features
The ARCSHAPE command in ArcInfo Workstation does not create polylineM features when converting a coverage route system into a shapefile. Route features are converted to simple polylines and the measure values are not maintained.
Several methods exist for creating shapefiles that contain polylineM features depending on the ArcGIS license available.
ArcInfo - Workstation
1. Use the DEFINE LAYER command to create a defined layer from the route feature class .