ABSTRACT
A review of implementations of soft transport policy measures (Richter et al. Citation2010) demonstrates their effectiveness in motivating car users to voluntarily switch travel mode. This paper review research that addresses questions of when and why these measures are effective. Long-term effects, synergies between soft and hard policy measures, assessments of individual differences, differences in determinants of participation and of changes in travel, generalizability, and nonquantified benefits are gaps in knowledge. Knowledge is also lacking about the cost-effectiveness of techniques such as providing motivational support to set change goals, requesting plans for how to change, and providing customized information.
ACKNOWLEDGEMENTS
This article was written while Jochen Richter in 2008 visited the Department of Psychology at the University of Gothenburg, Sweden, and the Service and Market Oriented Transport Research Group at Karlstad University, Sweden. Financial support was obtained through grant #2004–0297 from the Swedish Governmental Agency for Innovation Systems (VINNOVA). The authors thank Sebastian Bamberg, Dick Ettema, Satoshi Fujii, John Thøgersen, and Bertil Vilhelmson for their comments.