Riverdale is a borough in Morris County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 4,107, an increase of 548 (+15.4%) from the 2010 census count of 3,559, which in turn reflected an increase of 1,061 (+42.5%) from the 2,498 counted in the 2000 census.

Interstate 287 (I-287) is an auxiliary Interstate Highway in the US states of New Jersey and New York. It is a partial beltway around New York City, serving northern New Jersey and the counties of Rockland and Westchester in New York. I-287, which is signed north–south in New Jersey and east–west in New York, follows a roughly horseshoe-shaped route from the New Jersey Turnpike (I-95) in Edison, New Jersey, clockwise to the New England Thruway (I-95) in Rye, New York, for 98.72 miles (158.87 km). Through New Jersey, I-287 runs west from its southern terminus in Edison through suburban areas. In Bridgewater Township, the freeway takes a more northeasterly course, paralleled by US Route 202 (US 202). The northernmost part of I-287 in New Jersey passes through mountainous surroundings. After crossing into New York at Suffern, I-287 turns east on the New York State Thruway (I-87) and runs through Rockland County. After crossing the Hudson River on the Tappan Zee Bridge, I-287 splits from I-87 near Tarrytown and continues east through Westchester County on the Cross-Westchester Expressway until it reaches the New England Thruway. Within New Jersey, I-287 is maintained by the New Jersey Department of Transportation (NJDOT), and, within New York, it is maintained by the New York State Thruway Authority (NYSTA).