CORRELATION OF DRIVER CONFIDENCE AND DYNAMIC MEASUREMENTS AND THE EFFECT OF FOUR WHEEL DRIVE (4WD)

Engineers understand tha advantages of four wheel drive on low coefficient of friction surfaces. The advantages of four wheel drive for other surfaces and handling and stability are not well documented. When surveyed, customers say that four wheel drive feels safer for every road condition including dry roads. The object of this paper is to determine what factors contribute to the driver's feeling of safety and how different drive systems affect driver confidence. Three different drive systems were tested: front wheel drive, front wheel drive with traction control, and four wheel drive. Acceleration, steering angle, and yaw velocity were measured for these vehilcles on a wide variety of road surfaces. Subjective ratings of stability were made by professional test drivers and average drivers. Acceleration and handling tests on various surfaces were also measured. For the covering abstract of the conference see IRRD 875189.