To reduce and control the demand for private car use, various mobility management schemes have been developed. Mobility management can be categorized into two types: hard measures and soft measures. Hard measures as conventional methods have confronted financial issues or public opposition. In contrast, soft measures have been gradually increasingly discussed for changing the psychology of travelers for pro-environmental travel behavior change without appeal to reward and punishment in travel cost, but the mechanism of the effectiveness of soft measures in travel behavior has not been fully revealed. Hence, this research first compares the two types of measures to clarify the scope of needed knowledge for soft measures, that is, behavioral theories located in diverse sub-disciplines of psychology; in turn reviews behavioral theories and their applications in transportation to reveal the psychological processes underpinning the effectiveness of soft measures capable of changing the factors in the processes; and finally suggests that soft measures are necessary complements to hard measures in mobility management and that volitional factors and strategies in soft measures are in need of more attention and discussion.