Highway 1 is the Saskatchewan section of the Trans-Canada Highway mainland route. The total distance of the Trans-Canada Highway in Saskatchewan is 654 kilometres (406 mi). The highway traverses Saskatchewan from the western border with Alberta, from Highway 1, to the Manitoba border where it continues as PTH 1. The Trans-Canada Highway Act was passed on December 10, 1949. The Saskatchewan segment was completed August 21, 1957, and completely twinned on November 6, 2008. The speed limit along the majority of the route is 110 kilometres per hour (70 mph) with urban area thoroughfares slowing to a speed of 80–100 kilometres per hour (50–62 mph). Portions of the highway—the section through Swift Current, an 8-kilometre (5 mi) section east of Moose Jaw, and a 44-kilometre (27 mi) section between the West Regina Bypass and Balgonie—are controlled-access. Highway 1 serves as a major east–west transport route for commercial traffic. It is the main link between southern Saskatchewan's largest cities, and also serves as the province's main link to the neighbouring provinces of Alberta and Manitoba.

Alberta Provincial Highway No. 1, commonly referred to as Highway 1, is a major east–west highway in southern Alberta that forms the southern mainline of the Trans-Canada Highway. It runs from the British Columbia border near Lake Louise through Calgary to the Saskatchewan border east of Medicine Hat. It continues as Highway 1 into both provinces. It spans approximately 534 km (332 mi) from Alberta's border with British Columbia in the west to its border with Saskatchewan in the east. Highway 1 is designated as a core route in Canada's National Highway System and is a core part of the developing Alberta Freeway Network.