Canoe History Enthusiast
There were a variety of colorful 'hats' at the Northeast Chapter's paddle on Messalonskee Stream this weekend.
On a truck rig like Craig Johnson's, the carrying bars are far enough apart (8 feet) to greatly lessen the overhang and therefore greatly diminish the leverage that wind can bring to bear, making bow and stern lines unnecessary;
Racks have been known to fail, that's why the extra lines on the bow/stern.
With this said, if I'm only going a short distance, say 20-30 miles, I usually just do the 2 in the middle, but if I'm traveling farther or at speed, they get the bow/stern, for insurance.