direct access to westbound Glenmore and one must first exit to the east, proceed through a traffic light behind Calgary Auto Mall, and enter Glenmore Trail from the north side. At Highway 1, a split diamond interchange significantly slows east-west traffic even outside of peak hours, because all left turn movements must pass through three sets of traffic lights. This outdated interchange was Calgary's most dangerous road junction in 2011, with 234 crashes recorded. History Predecessor highways Prior to the completion of Deerfoot Trail, the historic alignment of Highway 2 in south Calgary was along Macleod Trail as an extension of 4 Street, parallel to a branch of the Canadian Pacific Railway from Calgary to Macleod. Macleod Trail has since been designated Highway 2A, on a routing largely the same as the original. It is now a busy expressway connecting Midnapore and other southwestern suburbs to downtown. The southernmost portion of the route from Highway 22X to De Winton would continue to serve as Highway 2 until completion of a Deerfoot Trail extension from its then southernmost point at the neighbourhood of Cranston to De Winton in 2003. In north Calgary, Highway 2 was originally composed of four present-day routes: Edmonton Trail, 41 Avenue, 48 Avenue, and Barlow Trail. Edmonton Trail is now a busy urban street on the west bank of Nose Creek through the neighbourhood of Highland Park, but its alignment in the 1920s had it curving to the northeast across the creek along present-day 41 Avenue to 48 Avenue where it continued east past the airport to Barlow Trail and north to Edmonton as Highway 1, later renamed to Highway 2. By the 1960s, Highway 2 had been realigned to follow Macleod Trail until turning east at Glenmore Trail before continuing north on Blackfoot Trail, veering to the northeast, and crossing the Bow River to join Barlow Trail to the north city limit. The former Edmonton Trail was re-signed as Highway 2A. As the airport continued to expand, 48 Avenue was reduced to an airport service road after the construction of McKnight Boulevard. Long after the completion and opening of Deerfoot Trail and its signing as Highway 2, the segment of Barlow Trail north of McKnight Blvd was closed in 2011 to allow construction of a new runway at Calgary International Airport. Early plans and construction Due to its quickly rising population in the 1960s, Calgary initiated