Route 284 leaves the borough of Sussex and enters Wantage Township, intersecting with Layton Road, Janice Drive, and Possum River Road.

Route 284 passes to the south of a lake, crosses over a branch of the Wallkill River and intersects with CR 642 (Bassets Bridge Road).

Just after the intersection with Route 642, the rural highway crosses over Quarryville Brook.

After crossing the Wallkill River branch again and the Appalachian Trail, Route 284 leaves New Jersey for New York and becomes NY 284.

New Jersey renumbered its Route 8N to Route 84 in March 1942 to match, in part to provide a single number for military caravans during World War II.