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Full-scale vehicle response tests were conducted on five vehicles using a crosswind disturbance test facility capable of providing a 35 mph wind over a nominal 120 ft test length. The vehicles were a Honda Accord, Chevrolet station wagon, Ford Econoline van, VW Microbus, and Ford pickup/camper. Results showed that passenger cars, station wagons, and most vans have virtually no crosswind sensitivity problems, whereas the VW Microbus, the pickup/camper (in winds higher than 35 mph), and cars pulling trailers do have potential problems. Key vehicle parameters dictating this yaw response sensitivity are the distance between the aerodynamic and tire force centers, tire restoring moment (including understeer gradient), and the basic aerodynamic side forces. A simple analytical relationship in these terms was developed to predict steady-state yaw rate in steady winds.

This paper presents the results of wind tunnel experiments in which force and moment data were measured for a variety of passenger and recreational vehicles in the presence of an intercity bus and a tractor plus semitrailer truck. The disturbed vehicles studied include a sedan, station wagon, compact sedan, van, truck/camper, and station wagon towing a trailer. A description of the apparatus is given along with details of the scale models used. Basic lateral-directional aerodynamic data for the passenger vehicles alone are shown for yaw angles up to 105 deg. Force and moment data for the vehicles in the presence of the disturbing truck or bus are shown for varying lateral separation and longitudinal positions of the two vehicles, as well as the relative crosswind angle. Critical conditions for a large disturbance due to a truck or bus are discussed.