Every private road back then failed financially
Every single one of them
how does a road fail financially? Are you saying they were toll roads and didn't pay for themselves or something? What about the turnpikes in Ohio, Penn, and KY that have paid for themselves enough times over they have stopped charging tolls in some places.
So your claim is that no private road ever in existence is still around? Or ?... I honestly don't know what you are trying to say.
Were you aware the two bridges into Canada from MI are privately owned? Probably not, or you wouldn't have made that claim. Pretty profitable too. Soooo, if you want to get into Canada from MI, and you only want to travel public roads, it's the tunnel or nothing.