 North of Maple Leaf Drive, the highway shifts northwestward, but then turns approximately northward at Highway 401. At the interchange with the 401, Highway 400 widens to twelve lanes. It continues north through Toronto, shedding two lanes at Finch Avenue. The congested section between Highway 407 and Langstaff Road in suburban Vaughan features a short collector-express system. The 400 / 407 junction is the only four-level stack interchange in Canada.
