Marilynn K. Yee/The New York Times

Subways should run more smoothly, but watch out for icy platforms.

What you need to know for Thursday: The sludge turns slippery, concerns over road salt, and the mayor’s pizza fork hits the auction block.

Nicole Bengiveno/The New York Times

New York’s sanitation commissioner, John Doherty, agreed to delay retirement to help the new de Blasio administration.