Interstate 278 (I-278) is an auxiliary Interstate Highway in New Jersey and New York in the United States. The road runs 35.62 miles (57.32 km) from US Route 1/9 (US 1/9) in Linden, New Jersey, northeast to the Bruckner Interchange in the New York City borough of the Bronx. The majority of I-278 is in New York City, where it serves as a partial beltway and passes through all five of the city's boroughs. I-278 follows several freeways, including the Union Freeway in Union County, New Jersey; the Staten Island Expressway (SIE) across Staten Island; the Gowanus Expressway in southern Brooklyn; the Brooklyn–Queens Expressway (BQE) across Northern Brooklyn and Queens; a small part of the Grand Central Parkway in Queens; and a part of the Bruckner Expressway in the Bronx. I-278 also crosses multiple bridges, including the Goethals, Verrazzano–Narrows, Kosciuszko, and Robert F. Kennedy bridges.
I-278 was opened in pieces from the 1930s through the 1960s. Some of its completed segments predated the Interstate Highway System and are thus not up to standards, and portions of I-278 have been upgraded over the years. In New York, the various parts of I-278 were planned by Robert Moses, an urban planner in New York City. The segments proposed tore through many New York City neighborhoods, causing controversy. Despite its number, I-278 does not connect to I-78. There were once plans to extend I-278 west to I-78 east of the Route 24 interchange in Springfield, New Jersey. This was canceled because of opposition from the communities along the route. The segment that does exist in New Jersey was opened in 1969. There were also plans to extend I-78 east across Manhattan and into Brooklyn via the Williamsburg Bridge; this would have been a second interchange between I-278 and its parent highway, but these plans were also thwarted. I-78 was also planned to extend east beyond I-278 to John F. Kennedy International Airport, and then curve northward on the Clearview Expressway, ending at the Bruckner Interchange in the Bronx. If these plans were fully completed, I-78 and I-278 would have met at three interchanges.