https://www.hikespeak.com/los-angeles/verdugo-mountains/

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

Sebastian Westberg submitted the route:

Roslagsleden (Roslags Trail) is a 190 km long hiking trail in Stockholm County, Sweden.