Penns Neck Circle is a traffic circle in the Penns Neck section of West Windsor Township, New Jersey, United States. It is located at the junction of US 1 and Washington Road (CR 571 and signed but unofficial CR 526). It is a major intersection, as Washington Road is one of three connections between US 1 and Princeton, New Jersey.While technically a traffic circle, the Penn's Neck Circle has been modified to closely resemble a traditional intersection.