There are 2 possibilities - the first and most likely is that the unpaved roads in OSM are not marked as unpaved.
The second possibility is that the program which converts OSM data into Garmin maps does not map the unpaved attribute into a format that Garmin can use.
A good option to help correct the first problem is to edit OSM and mark the unpaved roads that you know about. But that won’t quickly solve the long-term problem of how to mark all unpaved roads for OSM.
I haved looked at the MAPPING KEY and UNSURFACED ROAD is clearly a DASHED LINE.
Look at this road in Michigan (local road)
It’s SURFACE is GRAVEL, but the road is WHITE (Which I cannot find the definition in the MAP KEY)
Should it be a DASHED LINE?
I am about to add a TON of UNSET road surfaces in my local area SE Michigan, but it would SURE SPEED UP THE PROCESS, if I could see DASHED linetypes instead of having to select each road and then look at the SURFACE type.
I am tring to use iD editor and I am trying to select a ROAD to edit, but when I move my MOUSE to the LEFT SIDE to modify the attributes for that road, the MOUSE moves across other items and I loose the ROAD ATTRIBUTES on the LEFT side of the screen. I am in EDIT mode, but I cannot figure out how to EDIT the road I want.