diff --git a/lasso/project.py b/lasso/project.py
index 71a0270..f3a9cd6 100644
--- a/lasso/project.py
+++ b/lasso/project.py
@@ -389,6 +389,11 @@ def create_project(
             )
             base_roadway_network.split_properties_by_time_period_and_category()
         elif base_roadway_network:
+            if not isinstance(base_roadway_network, ModelRoadwayNetwork):
+                base_roadway_network = ModelRoadwayNetwork.from_RoadwayNetwork(
+                    roadway_network_object=base_roadway_network, 
+                    parameters=parameters
+                )
             base_roadway_network.split_properties_by_time_period_and_category()
         else:
             msg = "No base roadway network."