def destroy(self) -> None:
        """
        Destory func, release resource
        :return: None
        """
        self.clear_objects([v.id for v in self._traffic_vehicles])
        self._traffic_vehicles = []
        # current map

        # traffic vehicle list
        self.block_triggered_vehicles = []

        # traffic property
        self.mode = None
        self.random_traffic = None
        self.density = None

        Destory func, release resource
        :return: None
        
metadrive/manager/traffic_manager.py