OverpassAPI: order bus stops by id relation

Hi,

I'm trying to get all stops of a bus using line of bus and network name. After I choosed the direction and I use the id relation to get all bus stops as node. The problem is that these nodes are not ordered like bus line but an order without any logic.

An example of all node of bus 409 network ATAC (Rome) in json. http://overpass-api.de/api/interpreter?data=[out:json];(rel(1663894);node(r));out;

thank you