diff --git a/pyramid_routehelper/__init__.py b/pyramid_routehelper/__init__.py
index 04929d5..ace4936 100644
--- a/pyramid_routehelper/__init__.py
+++ b/pyramid_routehelper/__init__.py
@@ -229,7 +229,12 @@ def swap(dct, newdct):
     new_path = path + '/new'
     member_path = path + '/:id'
     
-    added_route_names = []
+    added_route_names = {}
+    
+    def add_route_if_new(self, route_name, path, **kwargs):
+        if route_name not in added_route_names:
+            self.add_route(route_name, path, **kwargs)
+            added_route_names[route_name] = path
 
     def add_route_and_view(self, action, route_name, path, request_method='any'):
         if request_method != 'any':
@@ -237,20 +242,14 @@ def add_route_and_view(self, action, route_name, path, request_method='any'):
         else:
             request_method = None
         
-        if route_name not in added_route_names:   # Check if the route name has been added already
-            self.add_route(route_name, path, **kwargs)
-            added_route_names.append(route_name)
-            
+        add_route_if_new(self, route_name, path, **kwargs)
         self.add_view(view=handler, attr=action, route_name=route_name, request_method=request_method, **action_kwargs.get(action, {}).get('default', {}))
         
         for format_kwargs in action_kwargs.get(action, {}).get('formatted', []):
             format = format_kwargs.pop('format')
             formatted_route_name = "%s_formatted_%s" % (format, route_name)
             
-            if formatted_route_name not in added_route_names:  # Check if the route name has been added already
-                added_route_names.append(formatted_route_name)
-                self.add_route(formatted_route_name, "%s.%s" % (path, format), **kwargs)
-            
+            add_route_if_new(self, formatted_route_name, "%s.%s" % (path, format), **kwargs)
             self.add_view(view=handler, attr=format_kwargs.pop('attr'), request_method=request_method,
                           route_name = "%s_formatted_%s" % (format, route_name), **format_kwargs)