The effect of eye-level street greenness exposure on walking satisfaction: The mediating role of noise and PM2.5.

While there are plenty of studies on the effects of neighborhood and park greenness on personal overall satisfaction and walking behavior, the relationship between street greenness exposure and walking satisfaction has received limited attention. Also, the possible pathways by which street greenness exposure affects walking satisfaction need to be further examined. To fill these research gaps, we measured eye-level street greenness using street view images, machine learning techniques and global position systems. A structural equation model was used to examine the mediating effects of objective noise and PM 2.5 exposure and related subjective annoyance, on the relationship between street greenness exposure and people's walking satisfaction. The results showed that street greenness exposure not only had a significant direct effect on walking satisfaction, but also has a significant indirect effect on walking satisfaction through subjective environmental annoyances (including noise and PM 2.5 annoyances) rather than through objective noise and PM 2.5 exposures. Besides physical activity and social interaction, the indirect effect of street greenness exposure on walking satisfaction through subjective environmental pollution annoyance accounted for about 17.39% of the total effect and cannot be ignored. These results suggest that the urban greenness layout policy should not only consider residential greenness but should improve people's environmental perception and walking satisfaction by allocating more greenness on streets with high noise and PM 2.5 levels. [ABSTRACT FROM AUTHOR]