5 to 3 Avenue in south Lethbridge, which was then Highway 3. It was later signed as 24 Avenue past Highway 5 (Mayor Magrath Drive), becoming Scenic Drive and continuing in a northwest direction to Highway 3 near downtown. In 1992, 43 Street in south Lethbridge was widened from two to four lanes, although it did not carry the Highway 4 designation at this time. Ordinarily, Alberta begins to consider upgrading to a divided highway when traffic levels reach 10,000 vehicles per day. The majority of Highway 4 remains well below this threshold, but it is a component of the CANAMEX Corridor in southern Alberta, to which Alberta had made a commitment to upgrading in the late 1980s. Plans for a divided highway were confirmed by 1989, and reiterated as a priority by annual reports published by Alberta Transportation through the 1990s. The highway was the southernmost component of what was then called the Export Highway, which also included Highways 2 and 3, which were given priority for twinning in the first half of the 1990s. In 1993, federal and provincial funding was announced for various twinning projects in Alberta, including the entirety of Highway 4. By 1996, work had begun on a section north of Coutts, and a $26 million commitment had been made by Alberta to a group of projects that included the widening of Highway 4 in Lethbridge. By 1998, a section south of Lethbridge to Highway 845 had been completed. For the majority of the highway, the newly constructed lanes carried northbound traffic and the existing road was converted to carry southbound traffic. Almost all work had been completed before the end of the decade. On September 18, 1999, Highway 4 was renamed the First Special Service Force Memorial Highway. The route was travelled between 1942 and 1944 by Canadian volunteers of the force to join their American counterparts for training at Fort William Henry Harrison near Helena in preparation for World War II. Several Canadian and American members of the force that came to be known as the "Devil's Brigade" were on hand in Milk River for the dedication of plaques for the route, and signs at both ends of the highway were erected. Interstate 15 between Sweet Grass and Helena had received the same name in 1996. The section of Highway 4 through Milk River was the last remaining section that was not a