Interstate 278 (abbreviate I-278) is an Interstate Highway in the U.S. states of New Jersey and New York. Despite its number, it does not connect to I-78, though a western extension was planned to I-78 east of the Route 24 interchange. The majority of I-278 is in New York City, serving local traffic; it passes through all five boroughs (though through Manhattan only because the Triborough Bridge crosses Wards Island, which is technically part of Manhattan). The portion that goes through New Jersey is sometimes called the Union Freeway.