It should be about 3 hours (without stops or traffic and doing the speed limit) from Bluewater Bridge in Port Huron to the Lewiston Bridge in Niagara.
Not sure the actual terminology in the US, but up here we have a little green ownership card the Motor Vehicle office issues (I assume the same thing as a pink slip). This is all I have ever been asked for (and that was once, the very first time we crossed with our new trailer). Not an authoritative answer but I was told you need the same thing you would give a cop when you get pulled over: License, Insurance and Ownership.
