The pedestrian environment is crucial for a vital and attractive city [1, 2], public health [3–7], and environmental sustainability [8, 9]. Furthermore, understanding how to shape pedestrian environments has become increasingly critical under global climate change [10–12]. Therefore, extensive studies have focused on the association between built environments and walking travel [13, 14]. However, the difficulty or high cost of capturing the varying built environments experienced by individuals during daily activities leads studies to use physical environmental attributes [15] or street characteristics of zones where individuals reside [16, 17], which may deviate from individuals’ daily activity areas. The common limitation has caused the lack of a consistent or quantified objective walkability index to identify environment walkability and its association with individual walking behavior [18].
Hence, research over the past two decades also considered individual reactions to physical features in the built environment so as to bridge the gap in capturing built environments experienced by individuals [19]. These psychological reactions constitute perceived environment walkability (PEW) as a set of more proximal determinants of walking behavior than physical features [19, 20]. Thus, PEW could replace variables of physical built environments and refine understanding of perceived built environments. However, PEW as psychological reactions could not be directly observed but measured by psychological scales.
Among PEW measurement tools, the Neighborhood Environment Walkability Scale (NEWS), established based on the American neighborhood environment for physical activity promotion, comprises comprehensive PEW factors, including individual psychological reactions to residential density, land use mix diversity and access, street connectivity, walking facilities, aesthetics, and pedestrian, traffic, and crime safety [21]. The NEWS has been widely applied to American cities [22–24], European and Australian cities [23], Hong Kong [25–27], and Japanese cities [28] for walking environment improvement.
The literature applying the NEWS has observed the association of the PEW factors with physical activity, walking time, life satisfaction, and affective factors. For example, residents in objectively defined high-walkability neighborhoods who perceived higher residential density, land use mix, street connectivity, aesthetics, and pedestrian/traffic safety had a longer physical activity time and lower body mass index (BMI) [21]. It was further observed that land use mix, residential density, walking infrastructure, aesthetics, traffic safety, and crime safety were positively associated with walking time for commuting to work; in contrast, aesthetics, land use mix, and residential density were positively associated with walking time for leisure [22]. Moreover, residents in high physical walkability neighborhoods reported higher perceived levels of residential density, land use mix, street connectivity, walking facilities, and traffic safety [25]. Considering walking purposes and gender differences, Inoue, Ohya [28] presented residential density and land use mix as the positive correlates of walking time for commuting to work, while aesthetics and traffic safety as the positive ones of walking time for leisure. The study also presented that high residential density and land use mix could interfere with women’s leisure walking. Yu, Cheung [26] identified that residents in high PEW neighborhoods had higher life satisfaction and happiness but lower loneliness. Consequently, the above studies have supported the effectiveness of PEW in explaining walking and life quality (including health, life satisfaction, and well-being). Furthermore, the sequential relationships between PEW, walking, health, and well-being or life satisfaction have been conceptualized by integrating empirical evidence [19].
1.1. Literature gaps
Similar research as mentioned above has supported that PEW can assess the walkability of physical environments and thus is associated with health and well-being. However, according to the latest systematic review of 42 empirical PEW studies by De Vos, Lättman [19], only three of these studies investigated the separate impacts of PEW on transport/utilitarian and recreational/leisure walking [29–31], and none examined the relationship between walking and health or well-being while distinguishing between transport and recreational walking. The deficiency may cause the following interrelated research gaps.
(1) Difference between environmental determinants of transport and recreational walking
Clarifying the differences in environmental factors influencing walking for different purposes is fundamental for shaping walkable environments for specific types of pedestrians. Pedestrians with different purposes may incorporate different sets of environmental factors into travel decisions because of having distinct destination types, route preferences, walking distances, and time constraints [32–35]. Thus, research has distinguished between commuting (i.e., to/from the workplace or school) and non-commuting walking [e.g., 36] and between walking for work and shopping [e.g., 37, 38] to identify environmental determinants. However, most prior studies have not elucidated the difference between environmental factors influencing transport and recreational walking. Although a few studies have distinguished between transport and recreational walking, additional evidence is needed for their conflicting findings on the impact of environmental factors [28, 39]. The lack has hindered the development of targeted strategies for promoting specific types of walking. Hence, measuring transport and recreational walking separately and exploring their associations with environmental factors can help elucidate the interaction between walkability and walking behavior [40].
(2) Difference between impacts of transport and recreational walking on life quality
Walking and walkable environment promotion has been widely advocated to enhance public health [41–43]. Although various benefits of total walking or exercise walking to life quality have been found [26, 44, 45], less is known about whether transport and recreational walking improve life quality. Insufficient understanding of the effects of undertaking various types of walking on life quality hinders the refinement of walking promotion policies to improve public health effectively. The difference between transport and recreational walking impacts may stem from heterogeneous environmental exposures, including pollution, noise, heat, greenery, and scenery, which depend on walking locations and places. Recreational pedestrians may have more flexibility in choosing locations and places, compared to the limited options for transport walking routes due to fixed workplace/school and service facility locations [36, 46]. Consequently, recreational walks may be more likely to occur in an environment perceived as better for one’s health. Hence, examining the associations of transport and recreational walking with life quality and revealing their difference can provide insights into promoting walking to improve public well-being.
(3) Impacts of sociodemographics on life quality via transport and recreational walking
Understanding how socioeconomics affect transport and recreational walking and subsequently impact life quality is crucial for developing tailored public health interventions for diverse communities [41]. For example, if a specific subgroup benefits more from recreational walking, policies could enhance walkability for recreational walking in areas with a higher proportion of the subgroup. However, for the associations of socioeconomics with walking behavior and life quality, investigations into the effects of car and scooter ownership are currently lacking; besides, the effects of age and gender are less clear and inconsistent, respectively [19]. These inadequacies might have led the conceptual model of the determinants and outcomes of PEW proposed by De Vos, Lättman [19] not to comprise sociodemographics. More importantly, prior studies examining socioeconomic impacts on life quality did not distinguish between transport and recreational walking [26], and those examining socioeconomic impacts on different types of walking did not explore life quality [28]. Conclusively, research has considered sociodemographics but insufficiently addressed their associations with walking for different purposes and life quality. Hence, a comprehensive investigation into the associations can facilitate the understanding of how sociodemographics affect life quality differentially via transport and recreational walking, as well as the development of tailored interventions in public health.
(4) Mechanism of influence of environment walkability for transport and recreation on life quality
Due to the abovementioned unclearness of the associations of transport and recreational walking with life quality, it is little known how environment walkability for transport and recreation indirectly affect life quality through walking, which has been considered a crucial issue in future research agenda [19]. Although several recent studies found links between environment walkability and life satisfaction [47–50] or satisfaction with health and life [51], two limitations existed therein: no distinction between walkability for recreational and transport and lacking the roles of transport and recreational walking in the relationship between walkability and life quality. Thus, walkability impacts on life quality should be further uncovered by examining the associations between walkability and walking for different purposes and life quality to underlie the benefit assessment of walking environment improvement measures.
1.2. Purpose of the present study
Based on the identified research gaps, existing studies have not offered a clear understanding of how environment walkability for transport and recreation differently influence life quality. The absence may impede the accurate assessment of the benefits of active transport environments on life quality. Therefore, to understand the associations between the built environment, transport and recreational walking, and life quality, this study applying PEW to assess the built environment aimed to explore (1) the heterogeneous factors in PEW for transport and PEW for recreation respectively affecting transport and recreational walking and (2) the respective impacts of both types of walking on life quality (BMI, health satisfaction, and life satisfaction), considering the influences of socioeconomics. The results could refine the mechanism of how the built environment impacted life quality. The most crucial contribution of this study was to provide transport and environmental planners with insights into life quality improvement by walking environment improvement measures.