The NY State Department of Transportation has 511, which gives updates about traffic and transit (plus has a trip planner and ride share info)—and which makes it a natural to put the information on Twitter. You can choose from a number of regions besides NY State— from the Adirondacks to Albany/Saratoga, from Long Island to Catskills/Hudson valley area—and for NYC, you can follow subways: 123, 456, 7, ACE, BDFV, G, JMZ, L/S, and NRGW.