The best way to get to Vasilyevsky Island from airport Pulkovo in St Petersburg is to use a ZSD - High-Speed Western Bypass. It takes about 25 minutes instead of 1 hour through the city center. That's the only way to get there during the night in the summertime. All the bridges are open in the central district. More information about the bridges in St Petersburg is here. The website of St Petersburg bridge company is here.