private void AddStop(string stopId, Coordinate location, string name, List<int> routes)
        {
            Stop s = new Stop(stopId, name, location);
            stops.Add(s.Id, s);

            foreach (int i in routes)
            {
                Route r = this.routes[i];
                s.routes.Add(r.Id, r);
                r.stops.Add(s.Id, s);
                s.SnapToRoute(r);
            }
        }