side of the existing post-tensioned concrete structures, as opposed to the conventional bridge widening practice of the expansion using a similar construction to the original bridge since post-tensioned concrete additions require falsework which in turn would close down Highway 407 ETR lanes for extended periods. The completed HOT lanes strech from south of Highway 409 to north of Rutherford Road. In conjunction with the widening work, and in anticipation of the opening of the extension north of Highway 7, exit numbers were added (still ongoing as of late 2021), starting with the northern sections of the highway. Vaughan Extension (2017–2021) An environmental assessment was completed on a northward extension of Highway427 to Major Mackenzie Drive to relieve traffic issues on Regional Road27 and 50, as well as provide improved access to the Canadian Pacific Intermodal Terminal, with construction beginning in May 2017. The project included HOT lanes as far north as Rutherford Road, and was scheduled to open in 2021, with the HOT lanes opening the following year. However, a pending legal dispute between the provincial government and the constructor delayed the opening of the extension in late April 2021. The extension was built by Link 427, a consortium of six companies that tendered the winning bid to Infrastructure Ontario, The project was estimated at a cost of $616 million, and included the design, financing, and construction of the extension, as well as its maintenance for thirty years. Construction required the periodic closure of eleven roads, and the permanent closure of Regional Road99. McGillivray Road was realigned at Rutherford Road, as was the intersection of Huntington Road and Major Mackenzie Drive. The extension north to Major Mackenzie Drive opened on September18, 2021, after the legal dispute was settled. Future There is a planned extension that would see the freeway pushed north to near Bolton to meet the proposed Highway 413, should that highway be constructed. The Highway427 Extension Transportation Needs Assessment Study examined further extensions; connections with the Bradford Bypass freeway, as well as Highway 400 and Highway 11 north of Barrie were considered. In the past decade, there has been little discussion of this highway extension due to concerns with traversing the Oak Ridges Moraine and Minesing Wetlands. Exit list See also Highway 427 BRT References Sources Bibliography External links Highway 427 Corridor Environmental Assessment Lost Road: Indian Line Road Highway 427 pictures and information Drone footage showing the