Only 175 km (108.7 mi) of this 666-km (413.8 mi) highway are covered with bitumen, and one has to drive the rest of the way on gravel. There are only 3 settlements, 3 refueling stations, and only 1 medical center throughout the highway. The local police force checks the presence of everything necessary for survival in the difficult Alaskan conditions for everyone who enters this route.