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Deteriorated roadway surfaces (potholes) encountered under everyday driving conditions may produce external vehicle disturbance inputs that are both destabilizing and highly transient. We examine vehicle behavior in response to such inputs through simulation. Idealized pothole geometry configurations are used to represent deteriorated roadway surfaces, and as environments in the HVE simulation suite of programs. Differences in vehicle response and behavior are cataloged, and the potential for destabilized vehicle behavior is examined, particularly under conditions in which only one side of the vehicle contracts the pothole. Vehicle types used in the simulation ensemble represent three classes of vehicles: a sedan, a sports car and an SUV. Results show that many combinations of vehicle speed, vehicle type and pothole configuration have essentially no destabilizing effects on the vehicle trajectory.

Vehicles running in wet conditions may experience hydroplaning of one or more tires. Hydroplaning can, and often does, change vehicle braking, acceleration and handling characteristics dramatically. Proper analysis of this behavior requires accommodating the clearing of paths for the rear tires that may result from the front tires engaging the water-coated surface first. In this work, tire overlap is calculated for vehicles in steady-state cornering maneuvers for generalized vehicle dimensions and tire characteristics.

Recent research on the effects of tire hydroplaning has examined the hydroplaning phenomenon and its potential effects on vehicle maneuvering from (1) geometric, (2) straight line braking/acceleration and (3) steady-state cornering maneuver points of view. In this work, we focus on the potential for hydroplaning during a transient maneuver: a standardized double lane change maneuver (ISO3888-1). Using both closed-form calculations and the HVE software suite, it is shown that partial hydroplaning has only a small-to- moderate potential to occur during portions of such maneuvers, but is not likely throughout the entire duration of the maneuver.

Vehicles operating in wet conditions may experience hydroplaning of one or more tires. Proper analysis of this behavior requires accommodating the clearing of paths for the rear tires that may result from the front tires engaging the water coated surface first. An experimental program was developed to study tire/road behavior during straight line braking maneuvers on a wet surface. Wheel rpm values were measured with operating ABS via CAN bus data. The experiments allowed qualitative estimation and visualization of the effects of path clearing on rear tires.

An experimental program to measure braking characteristics developed under emergency braking conditions by ABS-equipped vehicles was designed and performed. Variables examined included initial braking speed, vehicle type, tire pressure and data recording equipment utilized. All experiments were conducted on a closed airport taxiway constructed of sharp, brushed and heavily striated concrete. Tests were conducted with and without activated ABS systems on the test vehicles. Results showed that (1) with the ABS activated, faint roadway markings were visible only under a very few special circumstances, (2) tire/road μ-values and corresponding deceleration values varied only slightly for differing speeds and ABS conditions, (3) tire pressure made little difference in limited test results, and (4) there were differences in recorded results depending on the equipment used for data acquisition.