AbstractPackaging engineers need to be able to accurately determine the forces present in the shipping environment in order to protect packaged goods. The purpose of this study was to determine the vertical vibration levels measured in three separate truck‐trailer suspension systems; conventional leaf‐spring, conventional air‐ride and damaged air‐ride. The main conclusion reached in this study is that the air‐ride suspension when maintained gives lower power density (PD) levels on all road surfaces studied. A damaged air‐ride suspension and leaf‐spring suspension are very similar in response frequencies, although the damaged air‐ride produces higher vibration levels at lo