The crash, which involved a car and a motorcycle, was reported to the ambulance service at 5.30am on Monday morning.
Two emergency crews were called to the scene.
Paramedics tended to a man before he was was taken by ambulance to Altnagelvin Area Hospital.
Local diversions were put in place via Church Brae but delays are expected in the area.
Motorists are advised to seek an alternative route if possible.
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