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; 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; and wherein said control system comprises an adaptive cruise and wherein said control system controls the speed of the equipped vehicle to the reduced speed for traveling around the detected curve in the road and increases the speed of the equipped vehicle to above the reduce speed when the equipped vehicle is traveling along a straighter section of road after the curve in the road without deactivation of cruise control by the driver of the equipped vehicle.