Abstract: A method for classifying a road surface condition by estimating the maximum tire/road surface coefficient of friction and actively inducing acceleration or deceleration. In one embodiment, the induced acceleration/deceleration is provided by applying torque to the driven wheels of the vehicle. The speeds of the driven and non-driven wheels are measured. The tire/road surface coefficient of friction and the driven wheel slip ratio are calculated from the wheel speeds. The tire/road surface coefficient of friction and the wheel slip ratio are used to determine the slope of the wheel slip/coefficient of friction curve, which is used to classify the road surface condition.

Abstract: A navigation system (10) adapted for use with a vehicle (12) having an operator (14) includes a map database (16) presenting a current vehicle path, a locator device (20) communicatively coupled to the database (16) and configured to determine the location of the vehicle (12) and to associate the location with a position point within the database (16). The system (10) further includes an improved indicator (34) configured to predictively communicate an upcoming condition to the operator (14), determine a time-dependent-variable condition, compare a current condition of the vehicle (12) to the upcoming condition, and alert the operator (14) to a non-compliant comparison. The system (10) is further configured to receive preferences from the operator (14) and vehicle (12), so as to present a modifiable mode of operation.

Abstract: A method of assisting a driver to negotiate a roadway by identifying a curve from a map database (12); calculating an estimated negotiable speed for the curve (14); advising the driver of the upcoming curve (16); warning the driver if he attempts to negotiate the curve at a speed that is greater than the estimated negotiable speed (18); and controlling the vehicle (10) in order to attempt to safely negotiate the curve (20). When the curve is identified in advance rather in real-time, identification of the curve, and possibly one or more characteristics of the curve as well as the estimated negotiable speed, may be stored for subsequent access and use (22). Furthermore, the advisory, warning, and control behaviors may be varied based on pre-established or determined conditions (24). Additionally, the actual vehicle state as it pertains to entering and exiting the curve may be determined (26).

Abstract: A method for monitoring vehicle speed is provided. The method includes receiving a current speed of a vehicle and a current speed limit associated with a current location of the vehicle. A current speed range is calculated by comparing the current speed of the vehicle to the current speed limit. Operator alert preferences including a caution range and a warning range are accessed. An alert responsive to the current speed range and to the operator alert preferences is communicated to the operator of the vehicle. The alert includes one or more caution attributes when the current speed range of the vehicle is within the caution range. The alert includes one or more warning attributes when the current speed range of the vehicle is within the warning range. The alert includes one or more at speed attributes when the current speed range of the vehicle is not within the caution range or the warning range.