Padrões sazonais do risco de acidentes de trânsito no estado de São Paulo [Seasonal patterns in the risk of traffic accidents in the state of São Paulo]
DOI: 10.11606/t.6.2025.tde-27012026-161912
archive: archived pipeline: cataloged verified
Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)
Summary
This doctoral thesis investigates the influence of seasonal and chronobiological factors on the risk of traffic accidents in the state of São Paulo, Brazil. The research addresses a significant public health problem, as traffic accidents are a leading cause of injury, disability, and death. While infrastructure and behavioral factors are well-studied, the impact of biological rhythms and seasonality on driver performance remains understudied, particularly in Brazil. The study aims to clarify how seasonal variations, such as changes in photoperiod and temperature, affect driver attention, cognition, and accident occurrence. The methodology employed a quantitative, longitudinal design comprising three distinct studies. Study 1 was a scoping review examining the influence of seasonal and chronobiological factors on driver behavior. Studies 2 and 3 utilized secondary data collected from 2017 to 2019. Data sources included the São Paulo State Government databases for urban and highway traffic accidents, and the Social Security system for commuting accidents. The analysis incorporated climatic variables—average ambient temperature, precipitation, and photoperiod—as predictors in linear regression and analysis of covariance (ANCOVA) models. The average daily volume (ADV) of vehicles was included as a predictor or adjustment variable to control for traffic density. The results revealed a distinct seasonal pattern in traffic accidents that persisted even after controlling for traffic volume. Winter emerged as the season most strongly associated with an increase in accident occurrences. The findings suggest that chronobiological factors, particularly those related to winter conditions, significantly impact driver safety. The study highlights the role of reduced daylight and increased melatonin production during winter, which can induce drowsiness and impair cognitive alertness. Additionally, the research contextualizes these findings within broader issues of sleep deprivation and circadian misalignment, particularly among shift workers and those affected by seasonal affective disorders. The significance of this work lies in its contribution to the understanding of traffic safety from a biological perspective. By identifying winter as a high-risk period independent of traffic volume, the study underscores the need for interventions that address driver fatigue and alertness during seasons with reduced photoperiod. The author concludes that future research should explore the relationship between winter daylight variations and specific driver behaviors, such as sleep duration and drowsiness, to develop more effective prevention strategies. This thesis provides evidence-based insights for public health policies and traffic safety measures in São Paulo and potentially other regions with similar climatic conditions.
Key finding
A seasonal pattern in São Paulo traffic crashes — peaking in winter — persists after controlling for daily traffic volume, supporting a chronobiological contribution (reduced photoperiod, fatigue, sleep disturbance) over and above pure exposure.
Methodology
naturalistic
Sample size: 2017–2019 traffic-accident records for São Paulo state (urban + highway) plus federal Social Security commuting-accident records
Provenance
The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed. Discovered via tag_papers on 2026-05-30 (2 acquisition events logged).
| Stage | Outcome | Tool | Model | Prompt | Attempts | Completed |
|---|---|---|---|---|---|---|
| discover | success | — | — | — | 1 | 2026-05-07 |
| archive | success | canonical_url | — | — | 2 | 2026-06-03 |
| extract | success | cached | — | — | 2 | 2026-06-10 |
| clean | success | — | — | — | 1 | 2026-06-01 |
| chunk | success | — | — | — | 1 | 2026-06-01 |
| embed | success | — | — | — | 1 | 2026-06-02 |
| enrich | success | openalex | — | — | 3 | 2026-07-02 |
| promote | success | — | — | — | 2 | 2026-06-06 |
| summarize | success | llm | qwen3.6-27b-prismaquant | summ-v5 | 2 | 2026-06-10 |
| tag | success | vector_similarity | — | — | 17 | 2026-06-11 |
| verify | success | — | — | — | 2 | 2026-06-10 |
Summary generated by qwen3.6-27b-prismaquant on 2026-06-10; verification: verified.
Topics
Ranked by relevance to this paper. Hover a topic for its definition.