Second Avenue is located on the East Side of the New York City borough of Manhattan extending from Houston Street at its south end to the Harlem River Drive at 128th Street at its north end. A one-way street, vehicular traffic on Second Avenue runs southbound (downtown) only, except for a one-block segment of the avenue in Harlem .
The Second Avenue Subway (internally referred to as the IND Second Avenue Line by the MTA and abbreviated to SAS) is a New York City Subway line that runs under Second Avenue on the East Side of Manhattan. The first phase of this new line, with three new stations on Manhattan's Upper East Side, opened on January 1, 2017.
New York City (NYC), often simply called New York, is the most populous city in the United States.With an estimated 2019 population of 8,336,817 distributed over about 302.6 square miles (784 km 2), New York City is also the most densely populated major city in the United States.