... > objects > place > areas and regions > areas defined by humans > accessways > traffic routes > metro

... > objects > place > areas and regions > areas defined by humans > traffic areas > traffic routes > metro

... > objects > systems > systems of a society > traffic > land traffic > rail traffic > metro

... > events and action > action > moving > traffic > land traffic > rail traffic > metro

... > objects > systems > systems of a society > traffic > passenger traffic > public transport > rail traffic > metro

... > events and action > action > moving > traffic > passenger traffic > public transport > rail traffic > metro