Interstate 664 (I-664) is an auxiliary Interstate Highway in the US state of Virginia. The Interstate runs 20.79 miles (33.46 km) from I-64 and I-264 in Chesapeake north to I-64 in Hampton. I-664 forms the west side of the Hampton Roads Beltway, a circumferential highway serving the Hampton Roads metropolitan area. The Interstate crosses Hampton Roads via the Monitor–Merrimac Memorial Bridge–Tunnel (MMMBT) between Suffolk and Newport News. I-664 is connected to the other major cities of the metropolitan area—Portsmouth, Norfolk, and Virginia Beach—by I-264. The Interstate also has a connection to Portsmouth through State Route 164 (SR 164) and to Suffolk via U.S. Route 13 (US 13), US 58, and US 460.