New York State is home to more than 17,000 highway bridges, about 44 percent of them owned by the State Department of Transportation (NYSDOT), roughly 50 percent owned by municipalities, and the rest owned by state and local authorities (such as the State Thruway Authority), commissions (such as the Capital District State Park Commission), and ...
It can take a long time. Some employers move very quickly, and others move very slowly. People have been hired three hours or three months (or more) after interviewing. Moreover, hiring nearly always takes longer than employers expect it will; you should generally double or triple whatever timeline they give you.
Actually, there is no one-size-fits-all answer to the question of how long after the interview should you hear back. To answer this question, you should yourself decide as to the timeframe depending on the position that you have applied for and the company profile in the job market.