Extreme environmental temperatures and motorcycle crashes: a time-series analysis

Understanding motorcycle crash involvement: Insights from regular motorcyclists and food delivery riders in Vietnam

Motorcycles have become a primary mode of transportation in many low- and middle-income countries, including Vietnam, where they are widely used for personal transport and commercial activities. The growing reliance on motorcycles, driven by rapid urbanization and the rise of app-based delivery platforms, has brought economic benefits but also significant public health concerns due to the high incidence of road traffic crashes. This study, based on a questionnaire survey targeting regular motorcyclists and food delivery riders in Vietnam, examines and compares the factors contributing to crash involvement between two groups, regular and delivery riders. Random parameters models with heterogeneity in means and variances were employed to capture variability in respondent behaviors. The results reveal that psychological factors, such as negative attitudes toward traffic rules and intentions to violate rules, significantly increase crash involvement for both regular and delivery riders, with the effect being more pronounced among delivery riders due to job pressures. Conversely, positive attitudes reduce crash involvement but are less effective for delivery riders due to high time pressures and frequent distractions. Perceived severity of crashes and the swiftness of sanctions also play critical roles: higher perceived severity promotes safer behavior, while the threat of sanctions deters risky actions for both groups. Rider attributes, such as age, education, and income, influence crash involvement, with younger and lower-educated riders facing higher risks among both groups due to inexperience and limited traffic knowledge, while income effects vary between regular and delivery riders. Travel characteristics, such as travel durations of more than two hours, increase crash involvement due to fatigue and exposure, particularly affecting delivery riders who navigate complex urban environments and face frequent distractions. The findings also highlight the importance of addressing heterogeneity in data analysis for more comprehensive insights. Moreover, based on these results, various policy implications are provided to reduce traffic crashes and enhance safety for motorcyclists in motorcycle-dominated countries.

Global burden of road injuries and their attributable risk factors from 1990 to 2021: A systematic analysis for the global burden of disease study 2021

Objective: To systematically estimate the burden of road injuries and associated risk factors. Methods: Data on incidence, deaths, and disability-adjusted life years (DALYs) with 95 % uncertainty intervals, by age, sex, sociodemographic index, region, and country, from 1990 to 2021, were obtained from the Global Burden of Disease Study 2021. In addition, we obtained the numbers of DALYs and deaths attributed to risk factors. Joinpoint regression analysis was used to calculate the average annual percentage changes and 95 % confidence intervals (CIs). Results: In 2021, the incident cases of road injuries were 50.3 million (95 % uncertainty interval: 45.7 to 55.2) globally, with an age-standardized incidence (ASIR) of 627.8 per 100,000 population (95 % uncertainty interval: 570.6 to 688.1). From 1990 to 2021, the ASIR was decreased by an average of 1.52 (95 % CI: -1.55 to -1.49) per year. Substantial heterogeneity was observed, particularly among youth aged 25-29 years, males, and high-income North America. Road injuries caused 65.1 million (95 % uncertainty interval: 60.7 to 69.9) DALYs and 1195.7 thousand (95 % uncertainty interval: 1118.2 to 1275.7) deaths in 2021. High burden was observed in older people, males, Central Sub-Saharan Africa, and countries with low income. Motor vehicles (36.6 %) and pedestrians (36.8 %) were the main causes of death. In particular, 72.2 % of road injuries were attributable to occupational injuries for males, while 57.7 % were attributable to low bone mineral density for females. Conclusion: This study suggests a decreasing global burden of road injuries. Nonetheless, road safety remains a significant global public health issue.

A comparison of heat effects on road injury frequency between active travelers and motorized transportation users in six tropical and subtropical cities in Taiwan

Road traffic injuries (RTIs) pose significant public health threats, particularly for vulnerable road users such as pedestrians and cyclists. While recent studies have revealed adverse impacts of heat exposure on RTI frequency among motorized road users, a research gap persists in understanding these impacts on non-motorized road users, especially in tropical regions where their vulnerability can be heightened due to differential thermal exposure, adaptive capacity, and biological sensitivity. In this study, we compared associations between high temperatures and RTIs across four different crash-involved modes of transportation-pedestrians, cyclists, motorcyclists, and car drivers in Taiwan. Leveraging data on RTI records and temperature conditions in Taiwan's six municipalities from 2018 to 2022, we conducted a city-time-stratified case-crossover analysis. We employed distributed lag non-linear models with conditional Poisson regression models to estimate temperature-RTI associations for each mode of transportation, adjusting for various weather factors and unmeasured spatio-temporal patterns. Our findings reveal that individuals using exposed, open transportation modes (i.e., pedestrians, cyclists, and motorcyclists) exhibited higher relative risks of heat-induced RTIs than car drivers, with non-motorized mode users showing greater susceptibility compared to their motorized counterparts. These elevated risks can be attributed to the absence of built-in cooling systems in open travel modes and the increased exertional heat stress implied in active travel. Our study contributes novel insights to a global concern related to climate change, extending its impact to road safety, a health outcome rarely studied in the context of a changing climate. Our findings are thus important, especially for regions where rising temperatures regularly approach or exceed human physiological limits related to heat tolerance in the coming decades. Additionally, our findings hold significance in the existing urban health literature, particularly within the context of the emerging era of micromobility-a category of low-speed, non-enclosed, and lightweight vehicles increasingly integrated into urban activities worldwide.

Motorcycle riders and pillion passengers injury patterns and in-hospital outcomes based on the National Trauma Registry of Iran

OBJECTIVE

Road traffic injury (RTI) is the second leading cause of death and disability, and motorcycle crashes rank as the first cause of traffic fatality in Iran. We aimed to compare various characteristics between traumatized motorcycle riders and pillion passengers registered with the National Trauma Registry of Iran (NTRI).

METHODS

This is a retrospective study of the NTRI, an ongoing multicenter trauma database built on a registry. This study included injured motorcyclists from six major trauma centers nationwide admitted between February 2017 and November 2023. Motorcyclists should have been hospitalized for RTIs and met the NTRI's inclusion criteria. We assessed patients regarding their demographics, clinical features, the pattern of injuries, and diverse in-hospital outcomes.

RESULTS

Of 54,342 registered patients in the NTRI, 7,594 motorcyclists were included. Of them, 6,636 (87.4%) were riders, and 958 (12.6%) were pillion passengers. Among all, 7165 (94.5%) were male, and 420 (5.5%) female (p < 0.001). Only 656 (9.9%) of riders and 24 (2.5%) of pillion passengers were wearing helmets (p < 0.001). Lone motorcyclist crashes led to injuries in 1,394 (21.2%) riders and 332 (35.5%) pillion passengers (p < 0.001). Glasgow Coma Scale (GCS) was 3 to 8 in 204 (3.1%) riders and 16 (1.7%) pillion passengers (p = 0.016). The most frequent pattern of poly-trauma was "head and thorax," with 43 (32.3%) riders and 5 (25.0%) pillion passengers (p = 0.362). Univariable logistic regression analysis showed that Intensive Care Unit (ICU) admission (OR = 0.78, CI 95% = 0.62 to 0.97, p = 0.028) and mechanical ventilation (OR = 0.58, CI 95% = 0.39 to 0.84, p = 0.004) were significantly lower in pillion passengers compared to motorcycle riders. After adjustment for age, gender, occupational status, and helmet use, being a rider or a pillion passenger didn't have a significant association with any of the in-hospital outcomes.

CONCLUSIONS

Motorcycle riders and pillion passengers sustain the same injuries in terms of pattern, severity, and in-hospital outcomes. Therefore, healthcare providers can approach them similarly. Since there is a high number of underage riders and helmets are not used commonly, there should be more police enforcement in this case.

The effects of weather factors on road traffic casualties: Analysis on provincial panel data of China from 2006 to 2021

Introduction

Road traffic injuries stands as a major concern globally, as they result in significant loss of life, economic impact, and erode trust in government and societal safety. The influence of weather on road traffic safety is undeniable, impacting road conditions, individuals, and vehicles. However, the specific influence of weather on road traffic casualties has seldom been explored.

Method

This study assesses the effect of weather factors on road traffic casualties in China from 2006 to 2021. Vector error correction models (VECM) were utilized to determine the Granger causality between weather factors and covariates. Furthermore, panel autoregressive distribution lag models (ARDL) were applied to quantify the association between weather factors and road traffic casualties.

Results

The findings indicate that rainfall and temperature exert a short-term negative impact on casualty risk, which intriguingly becomes positive in the long term. A standout discovery is the significant role of health investments, which are shown to reduce casualty numbers in both the short and long-terms. In the long run, the gross domestic product significantly enhances casualties, while expressway mileage notably decreases them.

Conclusions

These results demonstrate the significant influence of weather on road traffic casualties and highlight the critical roles played by factors such as gross domestic product, health investment, and expressway mileage. The evidence presented in the study underscores the urgent need for more effective strategies to mitigate road traffic casualties. Thus, some effective measures are proposed to reduce road traffic casualties. This study is conducive to the improvement of traffic in severe weather in China and provides guidance for traffic management departments.

Association between ambient temperature and economic burden of unintentional injury in Tianjin: a case-crossover study

OBJECTIVE

Unintentional injuries constitute a significant global public health issue with significant social and economic costs. Previous evidence suggests ambient temperatures are associated with unintentional injury occurrences. However, the impacts of ambient temperature on unintentional injury economic burden have received little research attention. The objective of the study was to examine the association between ambient temperature and economic burden of unintentional injury.

DESIGN

Time-stratified case-crossover study.

SETTING

This study was performed at Tianjin Hospital, the largest trauma centre in Tianjin, by applying a hospital-based time-stratified case-crossover study.

PARTICIPANTS

The 12 241 patients admitted with unintentional injuries and meteorological data were collected in Tianjin, China in 2021.

PRIMARY AND SECONDARY OUTCOME

The association between ambient temperature and unintentional injury hospitalisation was evaluated with a distributed lag non-linear model, further temperature-attributable economic burden of unintentional injuries was quantified, and adjusted for demographic characteristics, injury mechanism and injury location of injury.

RESULTS

The temperatures below 11.5°C were significantly associated with the increased risk of unintentional injury hospitalisation in Tianjin, in 2021. The effect was maximised on the current day. The relatively low temperature was responsible for 25.44% (95% CI 13.74, 33.09) of unintentional injury patients, and was associated with the number of unintentional injury patients (3114, 95% CI 1608, 4036). The relatively low temperature was associated with the excess economic burden for unintentional injury (¥197.52 million, 95% CI 102.00, 256.00; about 27.10 million dollars), accounting for 26.49% of the total economic burden. The cold temperatures generally had greater impacts on males (¥136.46 million, 95% CI 83.28, 172.42; about 18.67 million dollars) and the elderly (¥74.35 million, 95% CI 14.87, 102.14; about 10.24 million dollars).

CONCLUSION

The temperature was associated with approximately 3000 unintentional injury patients and ¥200 million (27 million dollars), accounting for 26% of the total economic burden in Tianjin, 2021.

The Impact of Climate Change on Road Traffic Crashes in Ghana

Despite the substantial injuries and fatalities from Road Traffic Crashes (RTCs), evidence of climate change's impact on RTCs in Ghana is lacking. This study assessed the impact of climate change on RTCs in Ghana by combining quantitative (Mann-Kendall trend tests, Continuous Wavelet Transform analysis, causal inference analysis) and qualitative (15 key stakeholder interviews) methods. The quantitative analysis employed monthly rainfall and temperature data (1991-2021) alongside RTC data (1998-2021) across 10 regions. While rainfall trends varied regionally, the wet season (April through mid-October) showed a strong link to crash severity for all regions across Ghana. Wavelet analysis showed higher crash severity in the wet season within every 2-8 months period in a particular annual year during the study period. Causal inference analysis revealed rainfall's stronger influence (3.59%) on fatal crashes during the wet season compared to temperature (0.04%). Key stakeholder interviews highlighted perceived changes in temperature and intense rainfall patterns affecting RTCs, especially during rainy seasons suggesting an association between increased rainfall and crash severity. These findings emphasize the multifaceted role of climate change on road safety and the need to address weather-specific risks.

The impact of apparent temperature on the emergency visits for traumatic fractures in Hangzhou, China

BACKGROUND

Traumatic fractures occur frequently worldwide. However, research remains limited on the association between short-term exposure to temperature and traumatic fractures. This study aims to explore the impact of apparent temperature (AT) on emergency visits (EVs) due to traumatic fractures.

METHODS

Based on EVs data for traumatic fractures and the contemporary meteorological data, a generalized Poisson regression model along with a distributed lag nonlinear model (DLNM) were undertaken to determine the impact of AT on traumatic fracture EVs. Subgroup analysis by gender and age and sensitivity analysis were also performed.

RESULTS

A total of 25,094 EVs for traumatic fractures were included in the study. We observed a wide "J"-shaped relationship between AT and risk of traumatic fractures, with AT above 9.5 °C positively associated with EVs due to traumatic fractures. The heat effects became significant at cumulative lag 0-11 days, and the relative risk (RR) for moderate heat (95th percentile, 35.7 °C) and extreme heat (99.5th percentile, 38.8 °C) effect was 1.311 (95% CI: 1.132-1.518) and 1.418 (95% CI: 1.191-1.688) at cumulative lag 0-14 days, respectively. The cold effects were consistently non-significant on single or cumulative lag days across 0-14 days. The heat effects were higher among male and those aged 18-65 years old. The sensitivity analysis results remained robust.

CONCLUSION

Higher AT is associated with cumulative and delayed higher traumatic fracture EVs. The male and those aged 18-65 years are more susceptible to higher AT.

Association between High Ambient Temperatures and Road Crashes in an Australian City with Temperate Climate: A Time-Series Study, 2012-2021

(1) Background: High ambient temperatures are associated with increased morbidity and mortality rates, and some evidence suggests that high temperatures increase the risk of road crashes. However, little is known regarding the burden of road crashes attributable to no-optimal high temperatures in Australia. Therefore, this study examined the effects of high temperatures on road crashes using Adelaide in South Australia as a case study. (2) Methods: Ten-year daily time-series data on road crashes (n = 64,597) and weather during the warm season (October-March) were obtained between 2012 and 2021. A quasi-Poisson distributed lag nonlinear model (DLNM) was used to quantify the cumulative effect of high temperatures over the previous five days. The associations and attributable burden at moderate and extreme temperature ranges were computed as relative risk (RR) and attributable fraction. (3) Results: There was a J-shaped association between high ambient temperature and the risk of road crashes during the warm season in Adelaide, and pronounced effects were observed for minimum temperatures. The highest risk was observed at a 1 day lag and lasting for 5 days. High temperatures were responsible for 0.79% (95% CI: 0.15-1.33%) of road crashes, with moderately high temperatures accounting for most of the burden compared with extreme temperatures (0.55% vs. 0.32%). (4) Conclusions: In the face of a warming climate, the finding draws the attention of road transport, policy, and public health planners to design preventive plans to reduce the risk of road crashes attributable to high temperatures.

Temporal Instability of Motorcycle Crash Fatalities on Local Roadways: A Random Parameters Approach with Heterogeneity in Means and Variances

Motorcycle accidents can impede sustainable development due to the high fatality rate associated with motorcycle riders, particularly in developing countries. Although there has been extensive research conducted on motorcycle accidents on highways, there is a limited understanding of the factors contributing to accidents involving the most commonly used motorcycles on local roads. This study aimed to identify the root causes of fatal motorcycle accidents on local roads. The contributing factors consist of four groups: rider characteristics, maneuvers prior to the crash, temporal and environmental characteristics, and road characteristics. The study employed random parameters logit models with unobserved heterogeneity in means and variances while also incorporating the temporal instability principle. The results revealed that the data related to motorcycle accidents on local roads between 2018 and 2020 exhibited temporal variation. Numerous variables were discovered to influence the means and variances of the unobserved factors that were identified as random parameters. Male riders, riders over 50 years old, foreign riders, and accidents that occurred at night with inadequate lighting were identified as the primary factors that increased the risk of fatalities. This paper presents a clear policy recommendation aimed at organizations and identifies the relevant stakeholders, including the Department of Land Transport, traffic police, local government organizations, and academic groups.

Ambient temperature and risk of motor vehicle crashes: A countrywide analysis in Spain

BACKGROUND

Some studies have documented that cold or hot ambient temperatures increase the risk of motor vehicle crashes. However, the number of existing studies is still limited, especially for the effects of cold.

OBJECTIVES

To estimate the relationship between ambient temperatures and risk of motor vehicle crashes in Spain, and to estimate the same association when restricting to those crashes with driver performance-associated factors (namely distraction, fatigue, sleepiness or disease).

METHODS

We used data for the period 1993-2013. We conducted a time series analysis controlling for seasonality and trends and using the distributed lag nonlinear model framework to estimate nonlinear and delayed effects of up to 7 days. Analyses were conducted at the province level and combined using multivariate meta-analysis.

RESULTS

The study included 1,908,460 motor vehicle crashes, 37% of them with associated driver performance factors. The overall analysis showed that the risk of crashes increased almost linearly with temperature. The estimates of the cumulative effect of lags 0-7 when comparing the 99th percentile and the first percentile of temperature produced a relative risk (RR) of 1.15 (95% confidence interval (CI): 1.11, 1.20). The estimates were slightly higher when analyses were restricted to crashes with driver performance-associated factors (RR: 1.23, 95% CI: 1.17, 1.30). In some provinces that reached temperatures below 0 °C, an increased risk with cold temperatures was also observed. An added effect of both cold spell and heat wave periods was found only in the analysis of crashes with driver performance-associated factors (cold spells, RR: 1.029, 95% CI: 1.005, 1.053; heat waves, RR: 1.020, 95% CI: 1.002, 1.039).

CONCLUSIONS

The increase of temperature increased the risk of motor vehicle crashes in Spain. Measures aimed at reducing the influence of heat on the risk of motor vehicle crashes can have important benefits for public health.