Routing explorer can only be used to handle the data under DecimalDegree MapUnit, and it cannot deal with OneWay data.
So if your data require these features, please try to build RTG file like this:
RtgRoutingSource.GenerateRoutingData(rtgShapeFilePath, sourceShapeFilePath, routableShapeFilePath, BuildRoutingDataMode.Rebuild, GeographyUnit.Meter, DistanceUnit.Feet);
Attached is an utility for build your RTG file, you should want to did some changes for make it works for you.
BuildingOnewayRoadRoutingData.zip (13.4 KB)