About Union Township: The Township of Union is located in north-central Union County. It is traversed by a network of local and regional roadways including the Garden State Parkway, Interstate 78, US Route 22, and State Route 82 (Morris Avenue). The Union County municipalities of Elizabeth, Hillside, Springfield, Kenilworth, and Roselle Park, and the Essex County communities of Irvington, Maplewood, and Millburn border the Township.