It’s a veritable picnic these days getting across the 520 floating bridge. That’s the upside, one supposes, when one-third of the region’s drivers have abandoned it in favor of alternative routes. According to the state Department of Transportation, overall volume has plummeted by 34 percent — 18 percent during the morning commute and 25 percent in the evening.After six weeks of tolling, as reported by KING 5 News, it’s become clear that I-90 is taking the brunt of drivers’ reluctance to pay the toll, with a peak of $5 for those who pay by mail and $3.50 for Good 2 Go users.I-90 is getting 11 percent more traffic volume from those drivers who would normally use the 520.An additional 9 percent of cars and trucks, reports KING 5, are skipping both bridges, opting instead to drive north around Lake Washington on SR 522. At the same time, according to the DOT data, 5 percent of drivers have simply vanished — either choosing transit, carpooling, or just not crossing the lake at all.