Seasonal restrictions apply to motorized vehicles, which are typically banned on weekends from July until mid-September. So these are certainly the best days to enjoy the one-lane road. For more info, click here.
Once an ocean floor, the Gardetta Plateau was raised by tectonic forces that formed the Alps range. It is a site of great geological interest where fossil ripple marks and dinosaur footprints are visible in several spots although, for conservation purposes, these aren't advertised much. To learn about opportunities for guided discoveries see here, or here.
For centuries, the plateau has been strategic for the defense of borders and some of the defensive features are visible today such as bunkers and barracks dating back to the 18th century.
This is an unpaved one-lane road, that's very rough in several points. For reference, also see the Gardetta Plateau Loop featured ride.