A multi-camera vision system for a vehicle includes a plurality of cameras viewing exterior the equipped vehicle and at least one non-visual sensor sensing exterior of the equipped vehicle. Captured image data and sensor data are provided to a central data processor. At the central data processor, image data is fused with sensor data and processed in order to detect vehicles that are present external the equipped vehicle. The central data processor includes a digital signal processor operable to process data at a data processioning speed of at least 30 MIPS. Via processing at the central data processor of image data and sensor data, a potential hazard present exterior the equipped vehicle is determined to exist. The potential hazard arises from presence of rear-approaching traffic in at least one of (i) a side lane to the equipped vehicle and (ii) a rear lane to the equipped vehicle.