This study was the first to attempt an integration of social cognitive, perceived environment, and personality factors to predict leisure-time walking behaviour. Overall, the results complimented prior findings in each of these domains while extending the existing literature on walking.
As hypothesized, the perceived environment, but not personality, was associated with walking. Specifically, close proximity to retail infrastructure, quality of the walking infrastructure, and the aesthetics of the neighbourhood were correlates of walking. These findings parallel general environmental and PA research [18–22, 64]. The results for proximity to retail and neighbourhood aesthetics also replicate prior work focused in British Columbia  and the addition of quality walking infrastructure may represent the larger variability in the sampling frame (i.e., from City of Victoria to the entire province of British Columbia). Also similar to prior findings with environmental variables, the effect sizes are in the small range . Small effect sizes are likely important to public health initiatives , thus it may be prudent for community planners to consider these factors during neighbourhood design and revitalization projects.
The null finding for an extraversion-walking relationship replicates prior work , but the current study extends this finding to conscientiousness and neuroticism in a population sample. The indication that walking is unrelated to personality should be considered a positive, because its impact on human behaviour may be fundamentally basic/endogenous and difficult to intervene upon .
Our main analysis integrated the environmental characteristics salient to walking within a TPB model that also included a planning construct. Overall, this integrated model explained 25% of the variance in walking which is similar to basic TPB and PA  and prior walking research [11, 12]. Of key interest, perceived proximity to retail predicted walking independent of the TPB. This result was different from the full mediation of this variable found in the only other study to apply the TPB , but small independent effects of the perceived environment on PA are common in existing social cognitive and perceived environmental integration research [23–25, 66]. The results suggest that participants who live closer to retail may end-up walking more than originally intended. From a theoretical perspective, the result does not completely support the mediation tenet of variables "external" to TPB structure. Indeed, the finding supports a recent model suggested by Fishbein  whereby the environment may affect behaviour independent of initial intention. The hypothesis that some PA is incidental, and dependent upon ones environment, is also a fundamental tenet of social-ecological models . These results, in concert with most prior work, provide support for this theorizing.
Still, the largest predictor of leisure-time walking was one's intention to walk. Thus, walking is primarily a motivation-based behaviour. In turn, walking intention was predicted by affective and instrumental attitudes and PBC, and the effects of walking infrastructure quality and aesthetics were subsequently mediated by attitudes. The four studies that have applied the TPB to understanding walking all differ in their relative contributions from attitude, subjective norm, and PBC constructs [11–13]. Most notable, differences appear to be in the attitude construct, where two studies have shown attitudes as predictors of walking intent/behaviour (present study and ) and two studies have not [12, 13]. This is probably due to measurement differences in the definition of walking (i.e., sustained leisure-time walking compared to total walking). Total walking may be largely incidental to ones appraisal of the behaviour because it is fundamental to mobility of any kind and for multiple purposes. By contrast, sustained walking during one's leisure-time would seem more dependent upon the appraisal of the behaviour itself. Future research is needed to test this conjecture.
Another interesting finding in this integrated model was the null effect of planning on walking. Planning has had relatively consistent support in the health behaviour literature as a construct that either augments or even mediates intention-behaviour relations . This was the first study to apply the planning construct to walking within a TPB framework, but our findings are almost an exact replication of Rhodes et al. . Three factors may be contributing to this result. First, planning may not be particularly important to walking independent of motivation itself. Walking is noted for its ease to physically perform, access, and low cost. Perhaps planning is not as essential to regular walking because one does not need to overcome these barriers. Some evidence of this theorizing is also present from the null effect of PBC on walking independent of intention. Second, from a methodological perspective, intention and planning may be too collinear to produce unique contributions from each. In these data, intention and planning correlated r = .76, despite attempts to separate their measurement domains. Thus, although distinctions between the two constructs can be made theoretically, participants may not have drawn the same distinctions when responding to the items. Third, planning may be more critical for the initial behaviour change process and not a general construct within the TPB model. A vast majority of the population are in PA stasis (i.e., not changing their PA over short periods of time) , and this may attenuate the effect that planning has on those who are actually changing their walking behaviour. Future research is needed to test these possibilities.
A second purpose of this study was to evaluate planning, conscientiousness, and proximity to recreation as moderators of the intention-behaviour relationship. All of these variables have been shown to moderate this relationship in prior work [11, 33, 38], but they have not been combined to partial-out potential redundancies or to create an integrated model. As hypothesized, conscientiousness and proximity to recreation both moderated the intention-walking relationship. The overall size of this effect was modest (i.e., 2% variance explained) but interactions in survey designs are often difficult to identify due to limited range in the extreme cells . Thus this effect should be considered meaningful. The effect of close proximity to recreation facilities and parks on the intention-walking relationship suggests that those individuals who live closer to recreation have an easier time translating intentions into action. This may be because close proximity improves the ease of acting on one's intentions or because it cues people to follow through with their initial motives. Regardless, the result may have a practical application for regional and community planners: it appears increasing recreation land-mix may help close the intention-walking gap.
For conscientiousness, less conscientious individuals showed a lower intention-behaviour relationship than their moderate and high conscientiousness counterparts. This makes sense, as conscientious people are considered dutiful, achievement-oriented and orderly; following through with one's intentions seems a logical course of action for conscientious people. What was surprising, however, is that planning did not moderate this intention-walking relationship. Although this null finding has been reported before , planning has been cited as the potential mechanism, and even a possible intervention for the conscientiousness interaction with intention and behaviour [37, 38]. This null finding, therefore, does not support prior theoretical conjecture. Although experimental testing is needed, it may be that conscientiousness affects the intention-behaviour gap on a basic motivational (e.g., achievement striving) rather than an instrumental (e.g., organization, planning) level.
This study needs to be interpreted within the context of its limitations. First, the sampling frame of British Columbia (BC) may not generalize to other regions. BC is the most active province in Canada  and its two major cities feature mild climates. Second, although the sample obtained for this research was representative of the BC adult population in terms of sociodemographics  and PA , the baseline survey response rate was modest and the subsequent attrition rate was high. If differences in terms of PA cognitions and behaviour exist between those who completed the questionnaire and those who did not, it will bias our results. Finally, the walking measure was self-report which can introduce measurement error, particularly with lower intensity activities like walking. Future replication research using objective measures (e.g., pedometry, accelerometry) would be desirable.