A type of bridge consisting of connected floating concrete pontoons that are anchored to the bottom of the waterway they cross. Western Washington posesses most of the world's floating bridges: The Hood Canal Bridge, The Gov. A.D. Rosellini Evergreen Point Floating Bridge ("The 520 Bridge") and the twin I-90 floating spans. All of these bridges have "high rises" at either end that allow ships to pass underneath, and all except the I-90 spans have draw sections in the middle that open for larger traffic.