Driving Roads / Tail of the Dragon

It packs 318 curves into 11 miles with no intersecting roads or driveways, making it America's most famous sports-car and motorcycle road. It runs about 11 miles along US-129 at Deals Gap in Tennessee / North Carolina. Drive time: about 30 minutes one way.
Best time to go: Open all year; spring through fall is the main season, with fall color in the Smokies from late September.

Sources: Length · High point · Best time. Drive time is the route time for the mapped route without stops, from Mapbox.
Record the full 11-mile Deals Gap run and the whole line lands on your map, with the time and distance in your drive log. This is a smooth-cornering road, not a speed road.
The posted limit is 30 mph and the road is heavily patrolled; ride within your skill and stay in your lane on blind curves.
Open Road keeps every drive: the route on a map, the time and the distance. On iPhone and Android.