Dance and transit united Sunday to lure, and transport, hundreds of people to a collection of free performances strung along San Francisco streets, parks and alleyways. The roving audience saw dancers writhe and roll on bleachers at Golden Gate Park, as trapeze artists swung in the background. They witnessed a hip-hop dance troupe take over a South of Market alley, and Japanese drummers and dancers frolic outside Kezar Stadium. And to get to all these places they took the N-Judah streetcar — plus the Muni bus substituting for it during repair work along the line.