Quad line or dual line won't go anywhere if one line breaks. If it's a single line kite or if all of the lines break the kite will travel downwind. How far it goes depends on the strength of the wind, the altitude from which the kite is released, whether the kite is framed or not, where the lines break and if there's enough line dangling to create drag or possibly snag on objects, and probably a few other factors that I haven't thought of. I've had two dual line kites break both lines. Both were parafoils -- a 1.4 and a 2.2 meter. The 1.4 snapped near the handles at an altitude of about 50 feet in a medium-high wind, and traveled about 100 yards before the lines snagged on a bush. The 2.2 lines snapped near the kite in a 35-mph gust at an altitude of about 80 feet and the kite traveled 300 yards and ended up about 50 feet up at the top of a tree.