County Route 509, abbreviated CR 509, is a county highway in the U.S. state of New Jersey. The highway extends 25.78 miles (41.49 kilometers) from North Avenue (Route 28) in Westfield to Straight Street (CR 504) in Paterson. For two small stretches – in Clifton at the interchange with Route 19, and in Paterson as it crosses over the Passaic River – CR 509 splits into separate northbound and southbound alignments. CR 509 intersects with the Garden State Parkway at Exit 138 in Kenilworth.