Merge pull request #218 from SANDAG/ABM3_traffic_assignment

Update traffic_assignment.py

src/main/emme/toolbox/assignment/traffic_assignment.py

@@ -1018,15 +1018,25 @@ def prepare_midday_generic_truck(self, scenario):
     #added by RSG ([email protected]) for collapsed assignment classes testing
     #this adds non-transponder SOV mode to SR-125 links
     # TODO: move this to the network_import step for consistency and foward-compatibility
+    # Modified 10.10.24 by CAR based on suggestion from Kevin Bragg of Bentley so that it
+    # can handle networks that have no HOV = 4 links
     def change_mode_sovntp(self, scenario):
         modeller = _m.Modeller()
+        netcalc = modeller.tool(
+            "inro.emme.network_calculation.network_calculator")
         change_link_modes = modeller.tool(
             "inro.emme.data.network.base.change_link_modes")
-        with _m.logbook_trace("Preparation for sov ntp assignment"):
-            gen_sov_mode = 's'
-            sov_mode = scenario.mode(gen_sov_mode)
-            change_link_modes(modes=[sov_mode], action="ADD",
-                              selection="@hov=4", scenario=scenario)            
+        spec = {
+            "type": "NETWORK_CALCULATION",
+            "expression": "1",
+            "selections": {"link": "@hov=4"}}
+        report = netcalc(spec, scenario=scenario, full_report=True)
+        if report["num_evaluations"] > 0:
+            with _m.logbook_trace("Preparation for sov ntp assignment"):
+                gen_sov_mode = 's'
+                sov_mode = scenario.mode(gen_sov_mode)
+                change_link_modes(modes=[sov_mode], action="ADD",
+                                  selection="@hov=4", scenario=scenario)            
 
     def report(self, period, scenario, classes):
         emmebank = scenario.emmebank