Called NYC Street Closures, it pulls information from a variety of city agencies, including the Department of Transportation (which handles work permits for groups like large contractors and Con Ed) and the Office of Citywide Event Coordination and Management. It's searchable by date and location, and a tab on the bottom allows readers to toggle between event closures and construction closures.
“We all know how frustrating it can be to wake up and find your street has been unexpectedly blocked off for a street fair, a parade, or any other event,” said Council Member Garodnick, the author of the bill that created this online tool, in a press release. “The least we can do is make sure that New Yorkers know in advance what is happening out there. This online tool will give all of us a chance to find the events when we want them, and to avoid them when we don't.”
One caveat: the map shows planned closures. So if work or an event has been cancelled due to weather, the map will still show the street as closed.