public void ClearRoad()
        {
            erRoad = erRoadNetwork.GetRoadByGameObject(road.objectReferenceValue as GameObject);

            if (erRoad == null)
            {
                Debug.LogError("No road gameobject specified");
                return;
            }

            // the mask didn't get refreshed with the road, it stayed the old one => according to raoul this helps:
            Object.DestroyImmediate(erRoad.gameObject.GetComponent <AwesomeTechnologies.VegetationMaskLine>());

            // delete all markers
            // TODO: find out how to do that properly
            while (erRoad.GetMarkerCount() > 0)
            {
                erRoad.DeleteMarker(0);
            }

            erRoad.Refresh();
        }