At 7,580 feet, Seattle’s Albert D. Rosellini Bridge already had the distinction of being the world’s longest floating bridge. Now, its replacement is even longer, by about 130 feet. Connecting Seattle to neighboring Bellevue across Lake Washington, the new six-lane bridge opened in April, marking the end of a $4.5 billion project that began decades ago. It replaces a four-lane version built in 1963 and is more weather- and earthquake-resistant. It also reduces pollution. New drainpipes have been added to capture oil, brake linings and pulverized tires, which under the old bridge had been leaking into the lake. Because of the lake’s depth and silty bottom, the bridge can’t be supported by columns. Instead, it’s built on 26 pontoons the size of football fields, which are equipped with sensors to detect leaks. For the floating bridge’s grand opening, thousands of people turned out to see it -- so many, in fact, that the state Department of Transportation declared the event “at capacity” and halted buses shuttling people to the structure. The old bridge is expected to be dismantled by the end of the year.