Trenton, New Jersey Trenton, New Jersey Trenton is the capital city of the U.S. state of New Jersey and the county seat of Mercer County. It was briefly the capital of the United States. The city's metropolitan area is grouped with the New York metropolitan area by the United States Census Bureau, but directly borders the Philadelphia metropolitan area and is part of the Philadelphia Combined Statistical Area and the Federal Communications Commission's Philadelphia Designated Market Area. As of the 2010 United States Census, Trenton had a population of 84,913, making it the state's 10th-most-populous municipality. The Census Bureau estimated that the city's
State highways in New Jersey the 1990s, the majority of special U.S. Highways were renumbered as state routes. "See:" List of Interstate Highways in New Jersey "See:" List of U.S. Routes in New Jersey "See:" List of state highways in New Jersey State highways in New Jersey In the U.S. state of New Jersey, the New Jersey Department of Transportation (NJDOT) maintains a system of state highways. Every significant section of roadway maintained by the state is assigned a number, officially State Highway Route X but commonly called Route X by the NJDOT and the general public. Interstate Highways and U.S. Highways are included in