Lickskillet Road (Boulder County Road 89) is said to be the steepest county road in America, with an average gradient of 14.2% (and grades up to around 18%) over just about 1 mile on a well-graded dirt road. The top of the road is at the town of Gold Hill, at 8286' elevation. The FKT route is 1.0 miles between the south side of the lowest driveway (just off Lefthand Canyon Drive) and the stop sign at the top. It can be done as an uphill slog or a quad-busting downhill. There are Strava segments for both, but they don't capture the full 1.0 mile route, and also Strava does not provide sufficient accuracy for FKT purposes on such a short route, so exact watch time should be reported as well as a Strava (etc.) track.
Down Strava segment: https://www.strava.com/segments/17563342
Up Strava segment: https://www.strava.com/segments/10104374