Final test

env/simple_intersection/simple_intersection_env.py

@@ -1213,3 +1213,12 @@ class SimpleIntersectionEnv(RoadEnv, EpisodicEnvBase):
         self.window = backup_window
 
         return new_env
+
+    @property
+    def n_others_with_higher_priority(self):
+        n_others_with_higher_priority = 0
+        for veh in self.vehs[1:]:
+            if veh.waited_count > self.ego.waited_count:
+                n_others_with_higher_priority += 1
+
+        return n_others_with_higher_priority