steve91 says secondary
tastrax says secondary
myself and AntBurnett say anything > track
shashp says track
Based on this we should tag it secondary.
@shashp When assessing a road’s suitability to drive on based on your vehicle type and experience, don’t inspect the highway=* tag, instead look at smoothness=, surface=, tracktype=* (which I’m happy to see used on a highway>track), 4wd_only=, width= as per Australian Tagging Guidelines/Roads - OpenStreetMap Wiki