1. A driver assistance system for a vehicle, said driver assistance system comprising: an imaging device having a field of view forward of a vehicle equipped with said driver assistance system and in a direction of forward travel of the equipped vehicle, wherein said imaging device is operable to capture image data; wherein said imaging device is disposed at or in an interior rearview mirror assembly of the equipped vehicle with a field of view through the windshield of the equipped vehicle; an image processor operable to process image data captured by said imaging device; wherein the equipped vehicle comprises a control system operable at least in part to control the speed of the equipped vehicle; wherein said control system controls the speed of the equipped vehicle responsive at least in part to a detection of a curve in the road ahead of the equipped vehicle via processing by said image processor of image data captured by said imaging device; wherein said control system controls the speed of the equipped vehicle to a reduced speed for traveling around the detected curve in the road; and wherein said control system increases the speed of the equipped vehicle to above the reduced speed when the equipped vehicle is traveling along a straighter section of road after the curve in the road.