the West Humber River. This project included the extension of Finch Avenue west from Humberline Drive to Steeles Avenue and was completed in late 1984. As part of the initial phase of Highway407, Highway427 was extended north to Highway7 in Vaughan beginning with the construction of the interchange between the two in 1988. With the interchange only half-completed, the extension was opened in late 1991. By 1994, the final at-grade intersections—the first being the signalized left turn from the southbound lanes with eastbound Highway409 which was replaced by a flyover ramp, and the second being at Morning Star Drive, where an overpass was constructed to extend the street across the freeway to Humberwood Boulevard—were removed, making Highway427 a fully controlled-access freeway for its entire length. Upgrades since 1990s In 2001-02, modifications were made to the interchange with the QEW and Gardiner Expressway. This included a new loop ramp from the Highway427 southbound collectors to the Gardiner, aimed at relieving the congestion in the express lanes created by the southbound collector-to-express transfer near Bloor Street, as the collector lanes originally lacked direct access to the Toronto-bound QEW (downloaded from the province in 1998 to become the part of the Gardiner). The Gardiner Expressway also received an off-ramp to Sherway Gardens, which necessitated an underpass to be implemented in the directional ramp from the Highway427 southbound express to the Hamilton-bound QEW. Arterial extension and widening (2008–2021) An four-lane arterial road designated as Regional Road 99 was opened in the autumn of 2008 by York Region. This road unofficially extended Highway427's northern terminus from Highway7 to a signalized intersection with Zenway Boulevard, and mainly served to provide improved access to Highway27 and Highway 50. York Regional Road99 was permanently closed on August8, 2020, to make way for the extension of Highway427 northwards to Major MacKenzie Drive (Regional Road 25), which also involved constructing an overpass for Zenway Boulevard to cross the extended freeway. A section of Highway427 between Campus Road-Fasken Drive and Highway 7 was expanded to four lanes in each direction. This project included the installation of high-mast lighting, median barriers, and the addition of high-occupancy toll lanes (HOT) in both directions, and was completed in 2021 in conjunction with the Vaughan Extension (see below). One of the challenges during this project was widening the Highway 427 bridges crossing Highway 407 ETR, with the solution being steel box girders added on either