Ok, so there's a couple misconceptions here. "High Speed Rail" is a commuter service, not freight. Small, high value goods might be worthwhile on a high speed rail line, but the heavy freight that makes up the bulk of truck traffic is I'll suited for high speed rail.

The other issue is where the freight is going. A lot of it isn't going far enough to make rail worth it. Take the Windsor border crossings, for example. A large portion of those trucks (if not most) are bringing car parts back and forth between plants in Windsor and Detroit.

Can't build a high speed rail between states. Can't even build one within a state. There's no way we're gonna get one between countries. Oil lobbiests will sue over every tiny thing until the whole project runs out of funding ten times over.