One sign its summer on the Outer Banks is when the speed limit is temporarily lowered at dusk and dawn on the William B. Umstead Bridge to protect roosting purple martins.
North Carolina Department of Transportation lowered the speed limit from 55 mph to 20 mph at dawn and dusk on the bridge known locally as the Old Manns Harbor Bridge that crosses the Croatan Sound.
Beginning Friday and continuing until the end of August, the west end of the bridge will be home to about 100,000 purple martins as they prepare for their annual migration to Brazil. The birds roost under the bridge at night, head out at dawn to feed and return at sunset. The flock is so large during its peak that it can be seen on radar.
The department has partnered with the Coastal Carolina Purple Martin Society since 2007 to educate the public about the flock and protect the birds and motorists. The state activates flashing lights and lowers the speed limit on the bridge at sunrise and sunset. The speed limit is monitored by law enforcement and allows motorists and birds safe passage across the sound.
Coastal Carolina Purple Martin Society has seen a dramatic decline in bird deaths around the bridge since the lights were installed and the speed limits lowered.
Motorists can use the Virginia Dare Memorial Bridge as an alternative to the Umstead bridge. Safely view the flock at Dare County’s multi-purpose pier at the west end of the bridge.