Nature-inspired visual interventions in metro stations and commuters' affective well-being: the mediating roles of perceived crowding and environmental comfort.

OBJECTIVE: This study examined whether restrained nature-inspired visual interventions in metro stations improve commuters' momentary affective well-being and whether perceived crowding and environmental comfort explain. METHODS: An image-based between-subjects experiment was conducted with 360 adult metro commuters, who were randomly assigned to conventional station scenes or nature-inspired intervention scenes. The intervention added coherent nature-inspired imagery and low-saturation green/blue-green tones to existing display and wall-surface areas while keeping spatial layout, passenger number and arrangement, lighting, signage, viewing perspective, and facilities constant. After viewing the assigned scenes, participants rated perceived visual quality, perceived crowding, environmental comfort, and momentary affective well-being. Independent-samples t-tests and serial mediation analysis were used to test the hypotheses. RESULTS: Compared with the conventional condition, the nature-inspired intervention condition produced lower perceived crowding, higher environmental comfort, and higher momentary affective well-being. Perceived crowding and environmental comfort each mediated the relationship between visual condition and affective well-being. The serial pathway was also significant: the intervention reduced perceived crowding, which was associated with greater environmental comfort and, in turn, better affective well-being. After the mediators were included, the direct effect of experimental condition was no longer significant. CONCLUSION: Restrained nature-inspired visual interventions can improve commuters' affective experience in metro stations by shaping appraisals of crowding and comfort. These findings extend the metro transit S-O-R model by showing how a targeted restorative visual strategy may ease perceived spatial pressure and enhance momentary well-being in high-density public transport settings. The results should be interpreted as evidence for the tested visual strategy rather than for all forms of station design improvement.