A Influência da presença de chuva no comportamento de condutores no meio urbano: um estudo naturalístico de direção

Abstract

This study analyzes the effects of adverse environmental conditions on driver behavior in urban settings, considering precipitation, lighting, and traffic flow variation. Six hypotheses were tested: three at the global level, assessing behavioral differences between rainy and dry conditions, daytime and nighttime periods, and peak and off-peak hours; and three at the individual level, examining how each driver responded to different precipitation scenarios. The empirical basis consisted of naturalistic driving data from the NDS-BR project, collected in the Metropolitan Region of Curitiba between 2019 and 2021, with continuous driving records under real traffic conditions. The analysis focused on three main dimensions of longitudinal behavior: (i) time spent in relative speed ranges (V1, V2, V3), (ii) normal and abrupt acceleration (A1 and A2), and (iii) normal and abrupt braking (F1 and F2). Descriptive statistics and non-parametric tests (Mann-Whitney, Kruskal-Wallis, and Dunn with Holm correction) were employed, complemented by the Hodges-Lehmann estimator and BCa bootstrap resampling with 2,000 replications to capture differences even in non-normal distributions.The results showed that precipitation was associated with reduced relative speed and less frequent moderate accelerations, as well as greater heterogeneity in abrupt accelerations and increased dispersion in abrupt braking. At night, moderate responses (A1 and F1) became more uniform, whereas abrupt behaviors (A2 and F2) exhibited higher variability, suggesting the influence of reduced visibility on more extreme reactions. During peak hours, behavior was more homogeneous and cautious, contrasting with the heterogeneity observed in off-peak periods.The individual-level analysis revealed that while some drivers maintained aggressive conduct even under adverse scenarios, others significantly adjusted their driving style, underscoring the role of personal factors in shaping responses to external conditions. It is concluded that all six hypotheses were confirmed to varying degrees, indicating that rainfall, lighting, and traffic flow significantly affect speed, acceleration, and braking. The study provides novel evidence in the Brazilian context and reinforces the importance of simultaneously considering environmental and individual factors in road safety planning and in the development of preventive strategies to reduce risks in urban environments.