Most automobile vibration testing is sinusoidal in nature, in which a regular pattern of rapid, slow and zero vibrations vary in a predictable pattern to mimic driving conditions. Hu's random vibration testing is more realistic. It uses several random processes to mimic different driving routes and styles - and hence mimic the stresses on the car. Although manufacturers have increased the speed of their vibration testing to accelerate the testing process, such tests do not consider the effect of a variable load on the car. Adding random vibrations to the accelerated test compensates for this deficiency.

Hu's new method also allows the user to specify the frequency range of the tests. This allows researchers to study the individual behaviour of components inside a car, and how they interact in a specific frequency range - just in case certain frequencies cause the structure to fail.