Abstract
Regarding on the evaluation of handling performance, subjective assessment is currently the only criteria to make the final judgement on the design of a vehicle system. The current vehicle dynamics concept employed to analyze objective tests or computer simulations with respect to the subjective assessment is based on a bicycle model. Since a new concept of vehicle dynamics regarding on transient steer characteristic presented here is based on subjective assessment, the concept can naturally explain the subjective assessment in terms of engineering language. This concept is also not limited to any linear assumption at all. The concept first starts with the primary target of the subjective assessment. Then, transient understeer and oversteer as well as steer transient are successfully formulated. Using this concept, the analysis result of an objective test or a computer simulation can be successfully related to the subjective assessment for the final design evaluation.