The process begins when MTO officials determine that a highway will soon be unable to safely handle the number of vehicles using it.
Planning is comprehensive.
A route that is technically sound and minimizes impacts to the environment and affected property owners is selected after extensive public consultation. The MTO recognizes the need to manage Ontario's forests, lakes, rivers, and wildlife resources responsibly. Plans for proposed four laning undergo a comprehensive environmental assessment process prior to approval, a process that can take two to three years to complete. Often, four laning is done by twinning the existing highway. This is done by constructing a new road parallel to the existing two lane roadway and dividing northbound and southbound traffic with the use of a median.