## create anchor points at intersections
arcpy.Intersect_analysis("LINES", "D:/Scratch/mpoints.shp","ALL", "POINT")
arcpy.MultipartToSinglepart_management("mpoints","D:/Scratch/anchors.shp")
arcpy.DeleteIdentical_management("anchors","Shape")
# calculate their distance along the line
arcpy.AddField_management("anchors", "CHAINAGE", "DOUBLE")

def Chainage(shp):
 mxd = arcpy.mapping.MapDocument("CURRENT")
 lr=arcpy.mapping.ListLayers(mxd,"lines")[0]
 with arcpy.da.SearchCursor(lr, 'Shape@') as cursor:
  for row in cursor:  geom=row[0]
 L=geom.measureOnLine (shp.firstPoint)
 return int(L)
#-------------------------
Chainage(!Shape! )

#sort anchor points accordingly
arcpy.Sort_management("anchors","D:/Scratch/sorted.shp", "CHAINAGE ASCENDING")

# Place ‘equally’ space points on BLUE line
arcpy.CalibrateRoutes_lr("LINES", "Name", "sorted", "Name", "CHAINAGE","D:/Scratch/routes.shp")
arcpy.MakeRouteEventLayer_lr("routes", "Name", "from_Excel", "LINE POINT m", "BLUE_POINTS", point_event_type="POINT")
# create cross-lines
arcpy.Merge_management("RED_POINTS;BLUE_POINTS", "D:/Scratch/merged.shp")
arcpy.PointsToLine_management("merged", "D:/Scratch/grey_sections.shp", Line_Field="M")
# compute their mid points and draw the line
arcpy.FeatureVerticesToPoints_management(“grey_sections", “D:/Scratch/mid_points.shp", "MID")
arcpy.PointsToLine_management("mid_points", "..Green_Line.shp", Sort_Field="M")

# create cross-lines
arcpy.Merge_management("RED_POINTS;BLUE_POINTS", "D:/Scratch/merged.shp")
arcpy.PointsToLine_management("merged", "D:/Scratch/grey_sections.shp", Line_Field="M")
# compute their mid points and draw the line
arcpy.FeatureVerticesToPoints_management(“grey_sections", “D:/Scratch/mid_points.shp", "MID")
arcpy.PointsToLine_management("mid_points", "..Green_Line.shp", Sort_Field="M")