This argument is tied in with jurisdictional concerns, but there’s an important distinction to be made between the political boundary, on the one hand, and the impact of the project on the environment, on the other.
Let’s start with the jurisdictional concerns and then move on to the environmental impact concerns.
It’s a well established political norm to work across political boundaries to address issues that may have an environmental impact. Perhaps the most prominent example of this is the Intergovernmental Panel on Climate Change (IPCC), which has members from 195 nations. A less well known, but much older example is the International Joint Commission, which was established in 1909 and works to address issues affecting the quality of water along the border between Canada and the United States. Much of The Great Lakes are overseen by this body.
Environmental impacts, we now understand very well, are often difficult to contain, particularly when they occur in the fluid dynamics of air and water, and so work across jurisdictional boundaries is crucial to address them.
A more local example of the importance of working across political boundaries to address environmental impacts is our Conservation Authorities, which are established according to the natural boundaries of watersheds, and so attempt to capture, in a sense, the environmental impact of our actions.
Now, to address the more localized impacts and whether a highway in Bradford will affect those of us living in Barrie.
Part of the rationale for building the highway is to accommodate the projected population growth in Simcoe County, not simply the growth that is expected in the Bradford area. The vehicle trips this project is intended to accommodate come, in large part, from surrounding municipalities, including Innisfil and Barrie, which sends commuters down the 400 highway toward Toronto and the GTA.
(As an aside, there have also been a number of comments made, including by the mayor of Innisfil, that discount the voices of those who don’t live in the immediate area. These voices come from communities the Bypass is meant to serve. Accordingly, the decision of whether to continue to pour public funds into highways and car-centric development will impact how communities are shaped in these surrounding areas, determining, for example, whether there’s money available to ensure residents there have access to well-connected transit and/or safe cycling and walking routes.)