4.1. Measurement Model
The measurement model, or confirmatory factor analysis (CFA), examines the relationship between manifest (observed) variables and latent factors. Confirmatory factor analysis (CFA) is conducted to assess the measurement model’s reliability and validity. Reliability is evaluated using Cronbach’s alpha and composite reliability, with values above 0.7 deemed acceptable [
61]. Validity is examined through convergent and discriminant validity: convergent validity is confirmed when the average variance extracted (AVE) exceeds 0.5 [
62], while discriminant validity is verified using the Fornell–Larcker criterion, requiring the square root of AVE to exceed inter-construct correlations [
63]. In this study, four latent constructs were specified: (1) built environment, (2) access to amenities by using public transit and/or walking, (3) quality of transportation, and (4) support for transit funding.
After accounting for missing values, the final sample size used for the SEM analysis was 742 out of the total 994 survey responses (
n = 742).
Table 5 presents the standardized factor loadings for each observed variable linked to the respective latent variables, along with composite reliability, average variance extracted, and Cronbach’s Alpha values. All items showed loadings above 0.7, except two indicators of the built environment (overall cost of living = 0.63, and sense of community = 0.69), and one indicator of quality of transportation (quality of public transit services = 0.61). As both these latent factors’ average variance extracted, composite reliability, and Cronbach’s alpha exceeded the respective thresholds of 0.5, 0.7, and 0.7, the variables were retained. Internal consistency reliability, assessed through Cronbach’s alpha and composite reliability, met the acceptable range of 0.6–0.95 [
64], confirming construct reliability. Convergent validity was also established, as all constructs had average variance extracted values above 0.5, indicating satisfactory convergence.
The next step involves assessing discriminant validity using the Fornell and Larcker criterion, with the findings presented in
Table 5. The results indicate that the average variance extracted for each construct exceeds its correlations with other constructs, confirming that each factor is conceptually distinct and captures a unique dimension of the model.
Finally, the Standardized Root Mean Square Residual (SRMR) and the Normed Fit Index (NFI) were employed to assess the overall goodness of fit, reflecting how well the proposed model reproduces the observed data. A lower SRMR value and a higher NFI value indicate a better-fitting model, suggesting that the structural model adequately represents the empirical relationships among the constructs. The threshold values for the SRMR should be less than 0.1 [
65] and the value for NFI should be ≥0.90 [
62]. For the developed model in this study, the SRMR and NFI values are 0.074 and 0.94, which are within the threshold ranges, indicating an acceptable fit.
4.2. Structural Model Results and Discussion
The structural model in SEM investigates the strengths and direction of the relationships between latent exogenous and endogenous variables. This study examines the direct effects of latent exogenous variables (built environment, access to amenities, quality of transportation, and support for transit funding) on community QOL and individual OLS. The study also investigates the direct effects of important observed exogenous variables (ease of travel, perceived transit importance, transit need/support, and area type) on both community QOL and individual OLS.
The area type variable in the SEM is measured on a 1-to-5 scale, where 1 represents urban areas and 5 represents rural areas. This scale is based on the RUCC (Rural-Urban Continuum Codes, 1–9), with some categories merged to ensure adequate sample distribution across the five levels. The model also estimates indirect effects of latent and observed exogenous variables through the mediating community QOL variable while accounting for the influence of sociodemographic characteristics on individual OLS.
Table 6 presents the statistical results of the structural model developed for this study. Access to amenities significantly improves perceptions of the built environment (Std. R.W. = 0.281,
p < 0.0001). This suggests that when people have better access to grocery stores, parks, or healthcare, they perceive their physical surroundings as more favorable and supportive of a high QOL. Urban planners should prioritize mixed-use development and enhance proximity to everyday amenities to improve the livability of its residents. The built environment latent factor has the strongest direct effect on community QOL (Std. R.W. = 0.457,
p < 0.0001). However, it has an insignificant direct effect on an individual’s OLS. Access to amenities significantly (
p-value = 0.013) influences the QOL of the residents at the community level, even though to a relatively lesser degree (Std. R.W. = 0.082). Communities with better public transit and walk access to everyday amenities (like grocery stores, schools, healthcare facilities, parks, and shops) tend to have a higher perceived quality of life among residents. The quality of transportation latent factor has a moderate effect on community QOL (Std. R.W. = 0.188,
p < 0.0001), significant at the 5% level, while it has an insignificant direct effect on an individual’s OLS. The third latent factor, “support for transit funding,” has a statistically insignificant effect on community QOL, but a significant (
p = 0.060) and moderate direct effect on individual OLS (Std. R.W. = 0.046).
These findings align with expectations, as the built environment, access to amenities, and quality of transportation represent broad societal indicators and therefore have a strong direct impact on community QOL. In contrast, support for transit funding reflects an individual’s perception of public transit funding from external sources (city, county, state, or federal) and has a significant direct effect on individual OLS.
Within the built environment latent factor, the most influential indicators were shopping and entertainment options, quality health care services, available jobs, and parks and recreation facilities (see
Table 4). Policymakers should prioritize enhancing these aspects of the built environment. Similarly, the top three factors contributing to the quality of transportation were the quality of walkability, bikeability, and traffic safety (see
Table 4). Investing in improving non-motorized transportation and improving road traffic safety will significantly improve community QOL.
Regarding transit funding, city, county, state, and federal governments should allocate necessary resources to public transit agencies to optimize service quality and enhance satisfaction with life for transit users.
Ease of travel impacts both community QOL and individual OLS, with a stronger effect on OLS (Std. R.W. = 0.163) compared to community QOL (Std. R.W. = 0.088). De Vos (2024) [
66] conducted a comprehensive study on ease of travel and found that it is associated with higher subjective well-being. Providing efficient and more easily accessible travel options that meet daily travel needs can enhance the QOL of residents at both community and individual levels.
Perceived public transit importance negatively affects community QOL (Std. R.W. = −0.073). This likely includes transit-dependent populations, such as lower-income individuals, people who cannot drive, those with disabilities, and people without their own vehicle [
5]. This finding suggests that in communities where residents perceive public transit as highly important, their overall QOL tends to be lower. The reason behind this finding may be that these communities experience inefficient or inadequate public transit options, leading to transportation challenges that negatively impact their daily life. Enhancing public transit services may improve their QOL.
Public transit need/support negatively affects individual OLS (Std. R.W. = −0.086), but has an insignificant impact on community QOL. This suggests that individuals who support more public transit services may feel the existing services are insufficient to meet their daily needs, leading to lower OLS. Additionally, people with greater transit needs are often low-income, in poor health, or unable to drive. The impact of community QOL on individual OLS (Std. R.W. = 0.298) is significant, indicating that a higher community QOL enhances individual life satisfaction.
Age, income, and health positively influence individual OLS, indicating that older individuals, those with higher incomes, and those in better health report higher life satisfaction. However, higher education and non-white status have a significant negative impact on OLS, which may be due to the higher goals and aspirations of more educated individuals or the systemic challenges faced by non-white populations. Gender also has a significant negative influence on an individual’s OLS, indicating women report slightly lower life satisfaction, possibly due to differential mobility constraints or safety perceptions.
The results emphasize that enhancing the built environment, access to amenities, transportation quality, and ease of travel can significantly improve both community and individual well-being. Urban and transport policies should promote walkable and well-connected neighborhoods that facilitate convenient access to essential destinations. Improving the comfort, reliability, and efficiency of public transport can further the community’s QOL and individual life satisfaction. The findings also highlighted the need for equitable mobility strategies that address unmet transit needs among vulnerable social groups, such as women, older adults, and low-income residents. Overall, integrated planning approaches that link land use, accessibility, and transportation equity are vital for fostering sustainable and inclusive communities.
Figure 4 provides a visual representation of the significant relationships shown in
Table 6, with standardized regression weights. Negative signs indicate the negative effects of independent variables on the respective dependent variables.
While the current findings are based on traditional measures of the built environment and transportation, it is important to acknowledge that the transportation landscape has been rapidly evolving in recent years. The emergence of electric vehicles (EVs), the integration of digital transport applications (e.g., real-time transit apps, mobility-as-a-service systems), and shared and on-demand mobility platforms are transforming accessibility and travel behavior. Moreover, the growing emphasis on sustainability and inclusion through active travel promotion, low-emission transport initiatives, and universal design offers new dimensions to community QOL. Future community livability surveys or similar national datasets should incorporate indicators reflecting these technological and policy transitions to better capture their influence on well-being outcomes.
4.3. Total Indirect Effects on Community QOL and an Individual’s OLS
SEM can assess both direct and indirect effects through mediating variables. In this study, the built environment and community QOL serve as the mediators (refer to
Figure 4). For mediation to be valid, three conditions must be met: (1) the independent variable must be significantly related to the mediator, (2) the mediator must be significantly related to the final dependent variable, and (3) the relationship between the independent variable and the final dependent variable should diminish after including the mediator [
67]. Additionally, the mediator must be theoretically appropriate. All these conditions were satisfied for the hypothesized mediating variables.
Table 7 presents the total indirect effects on community QOL and individual’s OLS. Access to amenities shows a significant positive indirect effect on community QOL (β = 0.128,
p < 0.001), indicating that better access enhances overall community well-being. For individual outcomes, built environment (β = 0.136,
p < 0.001), ease of travel (β = 0.026,
p < 0.05), and quality of transportation (β = 0.056,
p < 0.001) significantly and positively influence life satisfaction, suggesting that well-designed, accessible, and efficient transport environments contribute to individual well-being. In contrast, area type, public transit need, and support for transit funding show no significant indirect effects, while perceived importance of public transit has a small negative association (β = −0.022,
p < 0.05), possibly reflecting unmet expectations regarding transit quality or availability. These findings highlight the critical role of accessibility, travel ease, and transport quality in shaping both community and individual life satisfaction.