Looks to me like you never cross the border. But there are many thousands who must do it daily in places like Detroit and Buffalo. I went over two weeks after 9/11 and although car traffic was only a 20 minute wait, the trucks were backed up for miles.
Unless you want to build wall and pretend that Canada and Mexico don't exist, we have to find a better way to allow commerce while protecting from infiltration as best we can.
And just in case you want to do a Pat Buchanan rant that we don't need trade either north or south, I'd remind you that ranking our oil imports by country of origin is as follows --- #1. Canada. #2. Mexico. #3. Saudi Arabia.