A lot of books and sites list the Pan American Highway as the longest in the world as it connects alaska to brazil. The only problem is that 54 km of the road do not exist!
The largest road in the world is the trans canada highway. It stretches 4,860 miles across 5 time zones from Vancouver Island, BC to Newfoundland. It's suggested to not try to drive the whole thing in one day. Get a hotel.
