Testing of cars is done once, but the information is used both to qualify or disqualify cars and to compare cars in terms of their performance in six test categories: acceleration, top speed, vehicle dynamics, breaking, ergonomics and communications, and fuel economy. These six categories remain valid after 16 years of testing. The testing begins with a May meeting between the manufacturers and the Michigan State Police group which lays out the specifications for the coming year. Actual trials occur over a 2 day period. Details of this comprehensive testing are outlined.