The Canadian section of the road was delineated with mileposts, based on the road as it was in 1947, until 1978, and over the years, reconstruction steadily shortened the distance between some of those mileposts. That year, metric signs were placed on the highway, and the mileposts were replaced with kilometre posts at the approximate locations of a historic mileage of equal value, e.g. km post 1000 was posted approximately where historical Mile 621 would have been posted.
Reconstruction continues to shorten the highway, but the kilometre posts, at 2-kilometre (1.2 mi) intervals, were recalibrated along the B.C. section of road in 1990 to reflect then-current driving distance. The section of highway covered by the 1990 recalibration has since been rendered shorter by further realignments, such as near Summit Pass and between Muncho Lake and Iron Creek.
Based on where those values left off, new Yukon kilometre posts were erected in fall 2002 between the B.C. border and the west end of the new bypass around Champagne, Yukon; in 2005, additional recalibrated posts continued from there to the east shore of Kluane Lake near Silver City; and in fall 2008, from Silver City to the boundary with Alaska. Old kilometre posts, based on the historic miles, remained on the highway, after the first two recalibrations, from those points around Kluane Lake to the Alaska border. The B.C. and Yukon sections also have a small number of historic mileposts, printed on oval-shaped signs, at locations of historic significance; these special signs were erected in 1992 on the occasion of the highway's 50th anniversary.
The Alaska portion of the highway is still marked by mileposts at 1-mile (1.6 km) intervals, although they no longer represent accurate driving distance, due to reconstruction.
The historic mileposts are still used by residents and businesses along the highway to refer to their location, and in some cases are also used as postal addresses.
Residents and travelers, and the government of the Yukon, do not use "east" and "west" to refer to direction of travel on the Yukon section, even though this is the predominant bearing of the Yukon portion of the highway; "north" and "south" are used, referring to the south (Dawson Creek) and north (Delta Junction) termini of the highway. This is an important consideration for travelers who may otherwise be confused, particularly when a westbound travel routes southwestward or even due south to circumvent a natural obstacle such as Kluane Lake.
Some B.C. sections west of Fort Nelson also route more east-to-west, with southwest bearings in some section; again, "north" is used in preference to "west".