Another way to say beltway in New England. The infamous Route 128 was once called Circumferential Highway; similarly Interstate 495 was the Outer Circumferential Highway, and a Middle Circumferential Highway was also planned. Other existing Circumferential Highways are in Burlington, Vermont (Route 289) and Nashua, New Hampshire (unnumbered). Dartmouth, Nova Scotia also has one (Route 111).
Beltways in other areas of the US have also been called this, but the name is no longer used. The infamous Capital Beltway (Interstate 495) was originally known as the Washington Circumferential Highway. The beltway around Atlanta, Georgia (Interstate 285) was the Atlanta Circumferential Highway.