diff --git a/rmf_building_map_tools/building_map/level.py b/rmf_building_map_tools/building_map/level.py
index 3e45bcc6a..66b036aea 100644
--- a/rmf_building_map_tools/building_map/level.py
+++ b/rmf_building_map_tools/building_map/level.py
@@ -211,6 +211,10 @@ def add_edge_from_coords(self, edge_type, p1, p2, props):
                 ParamValue.DOUBLE,
                 props.get('speed_limit', 0.0)
             ])
+            edge.params['mutex'] = ParamValue([
+                ParamValue.STRING,
+                props.get('mutex', "")
+            ])
             self.lanes.append(edge)
         else:
             raise ValueError('unknown edge type!')
@@ -486,6 +490,10 @@ def generate_nav_graph(self, graph_idx, always_unidirectional=True):
                     l.params['speed_limit'].value > 0.0:
                 p['speed_limit'] = l.params['speed_limit'].value
 
+            if 'mutex' in l.params and \
+                    l.params['mutex'].value:
+                p['mutex'] = l.params['mutex'].value
+
             if 'demo_mock_floor_name' in l.params and \
                     l.params['demo_mock_floor_name'].value:
                 p['demo_mock_floor_name'] = \
@@ -503,9 +511,6 @@ def generate_nav_graph(self, graph_idx, always_unidirectional=True):
             if 'dock_name' in v1.params:  # lane segment begins at dock
                 beginning_dock = v1.params['dock_name'].value
 
-            if 'speed_limit' in l.params:
-                p['speed_limit'] = l.params['speed_limit'].value
-
             if always_unidirectional and l.is_bidirectional():
                 # now flip things around and make the second link
                 forward_params = copy.deepcopy(p)
diff --git a/rmf_traffic_editor/gui/edge.cpp b/rmf_traffic_editor/gui/edge.cpp
index dc09bcde3..aa208d611 100644
--- a/rmf_traffic_editor/gui/edge.cpp
+++ b/rmf_traffic_editor/gui/edge.cpp
@@ -132,6 +132,7 @@ void Edge::create_required_parameters()
       std::string());
     create_param_if_needed("demo_mock_lift_name", Param::STRING, std::string());
     create_param_if_needed("speed_limit", Param::DOUBLE, 0.0);
+    create_param_if_needed("mutex", Param::STRING, std::string());
   }
   else if (type == DOOR)
   {