AS said The Ross rail is also glued as well as spiked. AND there is a wood support under the rail.
Your point about the track spikes loosening IS only true if you use the Ross track at a "lift up bridge" where the Ross track on one side can rub against the track on the lift bridge. If the gap is too tight you can affect the Ross spiking.
To avoid that I Crazy-Glue the spikes down or use Gargraves track on either side of the gap with Three(3) (one for each rail) Gargraves Track Strip Connectors (#910-4 at Trainworld) on the non-moving side of the lift bridge..................I know TMI.