- Western Terminus:
- Hillside Avenue (NY 25) and Braddock Avenue (NY 25) in Queens
- Eastern Terminus:
- Jericho Turnpike (NY 25) in Old Westbury
- 7.25 miles
- Queens, Nassau
Hillside Avenue is an east/west route that runs parallel to Jamaica Avenue and Jericho Turnpike (NY 25) in eastern Queens and western Nassau. It is designated NY 25 from Queens Boulevard to Braddock Avenue. The NY 25B designation begins at Braddock Avenue. For most of its length, NY 25B is a four-lane road. In East Williston, it narrows down to two lanes and changes names to become East Williston Avenue. Leaving East Williston, NY 25B widens to four lanes and changes names to become Hillside Avenue again. Just east of Glen Cove Road (CR 1), Hillside Avenue merges into Jericho Turnpike (NY 25) and ends.