Understanding commuters' perceived accessibility and travel intentions under rainstorm warnings in Shanghai, China

Severe rainstorm has happened frequently in recent years and seriously disrupted urban accessibility. Rainstorm warning is an important strategy for mitigating the impacts of flood-related disasters. However, the influence of rainstorm warnings on travel decisions, particularly through the lens of accessibility perception, has received insufficient attention in the existing literature. This study aims to investigate how commuters' perceptions of accessibility are shaped, and how these perceptions influence travel adaptations under rainstorm warnings. We proposed an integrated conceptual model based on the framework of the Protective Action Decision Model (PADM). The model consists of a four-stage social-psychological process: perception of warning credibility, travel risk perception, self-efficacy perception, and accessibility perception. An internet-based survey with 1563 respondents were collected for model analysis during the rainy season in Shanghai, China. The results show that commuters with lower socio-economic status tend to exhibit lower trust in warning credibility, which correlated with higher risk perception, decreased self-efficacy, and lower perceived accessibility. Besides, subway, bus, and e-bike commuters generally reported lower perceived accessibility compared to car commuters. The results further reveal that perceived accessibility was positively correlated with the intention to travel and negatively correlated with the propensity to mode shifts, though it showed limited impacts on departure time choice. These results may benefit us to better understand commuters’ travel behavior change and enhance emergency preparedness under rainstorm warnings.