Applying the Campbell Paradigm to sustainable travel behavior: Compensatory effects of environmental attitude and the transportation environment

Both personal propensities and transportation-environment-based factors shape people's sustainable travel behavior. However, little is known about the interplay of these two types of factors. In contrast to many of the commonly used behavior models in transportation research, the Campbell Paradigm directly accounts for constraining or supporting effects of the transportation environment with the concept of behavioral “costs” and proposes an additive, compensatory interplay with a person's environmental attitude (i.e., attitude toward environmental protection). The current research (three studies, n = 529, n = 382, and n = 176) provides both quasi-experimental and experimental evidence for this compensatory hypothesis. Drawing on participants' self-reports, an online scenario, and behavioral observation, we exclusively found that the main effects of the transportation environment and a person's environmental attitude explained his or her sustainable travel behavior. In all three studies, the interaction effect was never significantly different from zero, and across studies (|rp| = .04), it was even significantly smaller than a conventional small effect. These findings support the Campbell Paradigm as a useful theoretical account and as a policy framework for inducing more sustainable travel behavior.