+ RoutingStep(const RoutingStep *);
+
+ void create_successors(std::list<RoutingStep> &) const;
+ static void create_successor(RoutingStep &, unsigned, unsigned, std::list<RoutingStep> &);
+ bool update_states();
+ bool check_deadlocks() const;
+ int get_occupant(Track &) const;
+ int find_next_train() const;