It branches off Greenock Road, with
NS4668 : Broom Hill to its left (west). The track is shown under better conditions in
NS4668 : Farm track east of Broom Hill.
My thoughts on looking at the track on the map were that it led to something that is no longer there; the obvious gap (see the 1:25000 map in particular) is at about
NS46636894, and the first-edition OS map, surveyed in 1857, confirms that a farm called Freeland(*) stood there. Freeland appears on OS maps until at least 1939.
By means of aerial photography, traces of a far older settlement were discovered in the fields to the right (east) of the track: see
Link at Canmore for aerial photos, and
Link at WoSAS for further description.
(*) Freeland Farm is presumably what is commemorated by the name of Freeland Drive in Inchinnan:
NS4768 : Path to Freeland Drive, Inchinnan. The farm appears on the Blaeu map of "Renfroana" (1654, but based on surveys c.1600) as Friland. It appears as Freeland on Roy's Military Survey of Scotland (c.1740s—50s).