William B. Umstead Bridge, Road bridge in Dare County, United States.

The William B. Umstead Bridge is a two-lane road bridge over Croatan Sound between Manns Harbor and Roanoke Island in Dare County, North Carolina. Built in 1955 by T. A. Loving Company of Goldsboro, it carries US 64 and has a 55 mph speed limit, reduced to 20 mph at dawn and dusk in July and August.

Plans to link the mainland with Roanoke Island began in the 1920s, when developers pushed to open the Outer Banks to tourism; private toll bridges followed in 1928 and 1930, and a free ferry ran from about 1940. Dare County Bridge 9 was built in 1955 by T. A. Loving Company of Goldsboro and dedicated to William B. Umstead on April 25, 1957. It was rehabilitated in 1966, bypassed by the Virginia Dare Memorial Bridge in 2002, and lost US 264 in September 2003.

The bridge is named for William B. Umstead, a former U.S. Representative, U.S. Senator and the 63rd Governor of North Carolina. Built in 1955 as Dare County Bridge 9 by the T. A. Loving Company of Goldsboro, it was dedicated to him on April 25, 1957.

The bridge carries two lanes of US 64 with a 55 mph limit, reduced to 20 mph at dusk and dawn in July and August for the purple martins. Drivers should watch for birds swarming low over the west end at those hours. The span was bypassed in 2002 by the Virginia Dare Memorial Bridge, so traffic is lighter than on the newer crossing.

Purple martins have roosted on beams under the bridge every July and August since it opened in 1955, gathering before their migration to Brazil. Drivers once killed many birds, so in 2007 the Coastal Carolina Purple Martin Society asked for the speed limit to drop from 55 to 20 mph at dawn and dusk; the change sharply cut deaths.