The pioneer road completed in 1942 was approximately 1,680 miles (2,700 km) from Dawson Creek to Delta Junction. The Army then turned the road over to the Public Roads Administration, which then began putting out section contracts to private road contractors to upgrade selected sections of the road. These sections were upgraded, with removal of excess bends and steep grades; often, a traveler could identify upgraded sections by seeing the telephone line along the PRA-approved route alignment. When the Japanese invasion threat eased, the PRA stopped putting out new contracts. Upon hand-off to Canada in 1946, the route was 1,422 miles (2,288 km) from Dawson Creek to Delta Junction.
The route follows a northwest then northward course from Dawson Creek to Fort Nelson. On October 16, 1957, a suspension bridge crossing the Peace River just south of Fort St. John collapsed. A new bridge was built a few years later. At Fort Nelson, the road turns west and crosses the Rocky Mountains, before resuming a westward course at Coal River. The highway crossed the Yukon-BC border nine times from Mile 590 to Mile 773, six of those crossings were from Mile 590 to Mile 596. After passing the south end of Kluane Lake, the highway follows a north-northwest course to the Alaska border, then northwest to the terminus at Delta Junction.
Postwar rebuilding has not shifted the highway more than 10 miles (16 km) from the original alignment, and in most cases, by less than 3 miles (4.8 km). It is not clear if it still crosses the Yukon-BC border six times from Mile 590 to Mile 596. Ref.