A narrative-systematic review of the incompatibility of the objective and perceptual components of the physical environment and its effect on physical activity (walkability)

Introduction

Most of the researches that investigate the link between the environmental components of neighborhood and the physical activity of the residents, focus on one of the objective and perceptual criteria and sometimes use these criteria instead of each other. While each of them has different impacts on travel behavior and physical activity. This has formed a new trend in the literature, which measure the compatibility between two objective and perceptual components, determine the way and extent of the effect of each on the levels of outdoor physical activity. Nevertheless, after two decades of extensive international efforts, few studies have been conducted in the country. So, the article tried to use systematic-narrative review approach to create a path from global experimental studies related to the pedestrian and health literature into domestic researches.



Methodology

The methodology of research is based on narrative-systematic review approach. Google Scholar, Pop Med, Scopus and Web of Science databases were used to find articles, so that the words "pedestrian", "perceptual", "objective", "inconsistency", "adaptation and "Non-compliance" was searched in the title of articles, keywords and abstract. Then, by reviewing these articles and repeating key words in them, subsequent searches were focused on words and concepts such as density, accessibility, mix of uses, and street connection and distance. Finally, by examining the most important assumptions of these groups, searches were conducted on physical activity and obesity in order to critically examine the evidence. The most important keywords that were searched in the third stage included "physical activity", "walking", "active travel", "travel behavior". In total, by removing similar articles among databases, 352 articles were selected for initial review. Then the irrelevant articles were removed by reviewing the title and abstract, and finally 102 articles were selected for full review. After a complete review and according to criteria such as limiting the topic to physical activity and its relationship with mental and objective components, the information of 43 articles was used for this review.



Results and Discussion

Generally, the research results showed that there is a low to moderate agreement between the variables of the perceptual and objective environment, and there are few factors that consistently have a level of agreement and compatibility. The selected studies can be divided into two groups according to objective criteria. Those who only compared different types of objective characteristics of the research participants' neighborhood units, and those who considered more detailed variables such as density, mix of uses, and street connectivity for objective pedestrian measurement. Studies that consider the effect of objective and perceptual walking on physical activity or walking, find stronger effects on perceptual walking than on objective walking, although both types of walking have significant effects. Some researches showed that the reason for the low conformity between the standards is the lack of sufficient development of the perceptual standards as the objective variables of measuring the environment of the neighborhood unit. Objective and perceptual criteria cannot be used interchangeably because they consider different sources of change in behavior. Cross-sectional studies prevent causation and temporal progression of effects (from the objective environment to perceptions to behavior). Although a randomized controlled trial is not possible in this field of research, quasi-experimental and long-term longitudinal studies are needed to clarify the extent and direction of the studied effects. One of the weak points of the studies is paying less attention to the place of physical activity. This causes the potential of places to do physical activity to be ignored: at home, near home or work, or anywhere. In addition, activities should be distinguished from each other. The results of some researches showed that the compatibility between residents' perception of pedestrian orientation and pedestrian score is dependent on the change of geographical location. Pedestrianization of suburban retail corridors, which have a high concentration of businesses, but have a mix of uses and weak pedestrian infrastructure, have been overestimated.



Conclusion

The findings answered the research questions: a) Is the effect of objective criteria and perceptual criteria on walking the same? b) Is the more the objective and perceptual criteria match each other, the higher the amount of walking or vice versa? c) What are the reasons for non-compliance between subjective and objective criteria? First, the research results showed that both objective and perceptual characteristics of the environment affect physical activity and walking, however, each has a different effect and cannot be used instead of each other. Second, the studies of this field try to create a synergy between the objective and perceptual environment by bringing people's mental perception closer to the reality of pedestrianized environments or areas with lower pedestrianization, so that the amount of walking and physical activity increases. Finally, it seems that the reasons for non-compliance between objective and subjective standards can be distinguished in two groups. The following suggestions were proposed as a research agenda for further studies in this field:

• Based on the results, importance of psychological factors (such as habits, impressions and priorities) in the adjustment or mediation of objective and perceptual criteria, future studies are suggested, in addition to considering individual components and social, use more advanced methods to measure direct and indirect and partial relationships. These variables may help to avoid unobserved variable errors and provide more explanations for some unusual results from the analyses.

• It is recommended to find out the causal relationships between individual effective components such as the mobility of people and social components such as the sense of local community during the time of residence on the perceptual criteria of the environment, to conduct longitudinal research and to follow the physical changes and its effect on walking.

• In addition, evaluating the effectiveness of multi-level strategies such as physical activity support infrastructures and citizens' awareness of these opportunities through mass media or signs on the perception of walking.