Sustainable transportation stage of change, decisional balance, and self-efficacy scale development and validation in two university samples.

Single occupancy vehicle (SOV) transportation is a key contributor to climate change and air pollution. Sustainable transportation (ST), commuting by any means other than SOV, could both slow climate change and enhance public health. The transtheoretical model (TTM) provides a useful framework for examining how people progress towards adopting ST. Short valid and reliable measures for ST decisional balance, self-efficacy, and climate change doubt were developed and their relationship with stages of change was examined. Two large university-based volunteer samples participated in measurement studies. Using multiple procedures, three brief internally consistent measures were developed: decisional balance, self-efficacy, and climate change doubt. The stages of change correctly discriminated both decisional balance and self-efficacy, as well as replicated hypothesized relationships. Climate change doubt did not vary by stages; however, it may prove useful in future studies. Results support the validation of these measures and the application of the TTM to ST.