- Western Terminus:
- Middle Country Road (NY 25) in Riverhead
- Eastern Terminus:
- Main Road (NY 25) in Riverhead
- 4.49 miles
Old Country Road is a bypass of the semicircular section of NY 25 in Riverhead, providing a more direct route for those passing through Riverhead who do not need to pass through the center of the town. It is a two- to four-lane undivided road with traffic lights. The Long Island Expressway (I-495) has its eastern terminus at Old Country Road. Motorists headed for the North Fork will usually follow the expressway east to the end, merge onto Old Country Road, and follow it to Main Road (NY 25). Nassau CR 25 and Suffolk CR 71 are both also called Old Country Road, but Suffolk CR 58 does not connect to either of them.