Risk factors for crash involvement in older motorcycle riders

Assessing the collective safety of automated vehicle groups: A duration modeling approach of accumulated distances between crashes

Ideally, the evaluation of automated vehicles would involve the careful tracking of individual vehicles and recording of observed crash events. Unfortunately, due to the low frequency of crash events, such data would require many years to acquire, and potentially place the motorized public at risk if defective automated technologies were present. To acquire information on the safety effectiveness of automated vehicles more quickly, this paper uses the collective crash histories of a group of automated vehicles, and applies a duration modeling approach to the accumulated distances between crashes. To demonstrate the applicability of this approach as a method compare automated and conventional vehicles (human drivers), an empirical assessment was undertaken using two comparable sources of data. For conventional vehicles, police and non-police-reportable crashes were collected from the Second Strategic Highway Research Program's naturalistic driving study, and for automated vehicles, data from the California Department of Motor Vehicles Autonomous Vehicle Tester program were used (105 crashes from 59 permit holders driving ∼2.8 million miles were used for the analysis). The results of the empirical study showed that automated driving was safer at the 95% confidence level, with a higher number of miles between crashes, relative to their conventional vehicle counterparts. The findings indicate that the number of miles between crashes would be increased by roughly 27% when switching from conventional vehicles to automated vehicles. Despite limited data which mandated a group-vehicle approach, this study can be considered a reasonable initial approximation of automated vehicle safety.

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.

Unhelmeted Riding, Drunk Riding, and Unlicensed Riding among Motorcyclists: A Population Study in Taiwan during 2011-2016

This study aimed to investigate the association between drunk riding, unhelmeted riding, unlicensed riding, and running-off-road (ROR) crashes. Multiple logistic regression was used to calculate the adjusted odds ratio (AOR) by using the National Taiwan Traffic Crash Dataset for 2011-2016. The results revealed that unhelmeted riding was associated with 138% (AOR = 2.38; CI (confidence interval) = 2.34-2.42) and 47% (AOR = 1.47; CI = 1.45-1.49) higher risks of drunk riding and unlicensed riding, respectively. The risk of unhelmeted riding increased with blood alcohol concentrations (BACs), and riders with the minimum BAC (0.031-0.05%) had nearly five times (AOR = 4.99; CI = 4.74-5.26) higher odds of unlicensed riding compared with those of riders with a negative BAC. Unhelmeted riding, drunk riding, and unlicensed riding were associated with 1.21 times (AOR = 1.21; CI = 1.13-1.30), 2.38 times (AOR = 2.38; CI = 2.20-2.57), and 1.13 times (AOR = 1.13; CI = 1.06-1.21) higher odds of ROR crashes, respectively. The three risky riding behaviours (i.e., unhelmeted riding, drunk riding, and unlicensed riding) were significantly related to ROR crashes. The risk of unhelmeted riding and ROR crashes increased with BACs.

The effect of motorcyclists' age on injury severities in single-motorcycle crashes with unobserved heterogeneity

INTRODUCTION

Due to the myriad of unique characteristics associated with motorcycle operation, motorcycle safety is a public health concern as complex as it is serious. National crash data suggest motorcyclists are 28 times more likely to be killed when compared to passenger car occupants. In the state of Florida, motorcycle crashes are 1.5 times more likely to result in the death of the rider, placing Florida among the top deadliest states for motorcyclists in the nation. Using police-reported data from 2016, this study addresses the complex and interconnected nature of the many characteristics associated with motorcycle operation by investigating the effect of age on motorcyclists' riding behavior as it relates to injury severity for single-motorcycle crashes in the state of Florida.

METHOD

To account for unobserved heterogeneity in the crash data, mixed logit models with heterogeneity in means and variances were estimated to model three injury severity outcomes (non-visible, severe, and fatal) for three age groups (under 30, 30-49, and 50 and above).

RESULTS

Model results indicate that age affects motorcyclists' safety perception and ability to assess risks, thereby influencing their involvement in risky behaviors. Characteristics unique to motorcycle operation-spatial characteristics, speed, motorcycle type, time of day, helmet usage, alcohol consumption, ejection from motorcycle, passenger presence, endorsement status, and lighting-are further complicated by their dependency on the characteristics of the individual motorcyclist. Age of motorcyclist indicates a relationship between motorcyclists' behavior and perceived safety.

CONCLUSION

The model results indicated that statistically significant parameters constituted different models and they were not equal across the age groups of motorcyclists: aged under 30, aged 30-49, and aged 50 and above. Through advanced econometric modeling, this study fills a gap in the existing literature and assists the safety professionals, motorcycle trainers, policymakers, law enforcement agencies, and roadway designers in developing countermeasures.

Association of Traumatic Injury With Adverse Pregnancy Outcomes in Taiwan, 2004 to 2014

IMPORTANCE

Literature has suggested that trauma among pregnant women is associated with an increased risk of adverse pregnancy outcomes. However, limited research has investigated the association of trauma with adverse pregnancy outcomes by using a national data set.

OBJECTIVE

To investigate the association between traumatic injury and adverse pregnancy outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study of pregnant women in Taiwan linked 3 data sets, the Taiwan Birth Registry, Household Registration Information, and National Health Insurance Research Database, from January 1, 2004, through December 31, 2014. Data, including the characteristics of pregnant women and infants, were extracted from the Taiwan Birth Registry data set; to obtain trauma data, this data set and the Household Registration Information data set were collectively linked to National Health Insurance Research Database data. The combined data set was analyzed from January to July 2019. Adverse pregnancy outcomes and premature delivery were defined using International Classification of Diseases, Ninth Revision, Clinical Modification codes.

EXPOSURES

The primary exposures of this study were 2 clinical variables related to injury during pregnancy: medical treatment in the emergency department (yes or no) and hospitalization (yes or no).

MAIN OUTCOMES AND MEASURES

The main outcome variable was adverse pregnancy outcomes, and the secondary outcome variable was premature delivery. Multivariate logistic regression models were used to investigate the association of injuries with adverse pregnancy outcomes after controlling for demographic characteristics and other pregnancy-related variables.

RESULTS

A total of 2 973 831 pregnant women (2 475 805 [83.3%] aged 20-34 years) were enrolled between 2004 and 2014, of whom 59 681 (2.0%) sought medical treatments due to injuries. Results of multivariate logistic regression models showed that women receiving emergency treatments more than once were 1.08 times as likely (adjusted odds ratio, 1.08; 95% CI, 1.05-1.10) to have adverse pregnancy outcomes than women who received no emergency treatment. Women with injury-related hospitalization were 1.53 times more likely (adjusted odds ratio, 1.53; 95% CI, 1.41-1.65) to have adverse pregnancy outcomes than women who did not sustain injuries. Furthermore, recurrent injuries were associated with a 572% increase in odds of premature delivery (adjusted odds ratio, 6.72; 95% CI, 2.86-15.80).

CONCLUSIONS AND RELEVANCE

In this study, trauma among pregnant women was associated with an increased risk of adverse pregnancy outcomes, as were hospitalization and emergency department visits due to injury.

Evaluating the Effects of Holidays on Road Crash Injuries in the United Kingdom

BACKGROUND

Research suggests that drivers tend to engage in risk-taking behaviours on public holidays. Studies that examined the association between holidays (or other special days) and fatal injuries are inconsistent. This study used UK STATS19 data to investigate the associations of nine public holidays on road crash casualties.

METHODS

This retrospective study assessed UK STATS19 crash data for 1990-2017. All casualties from two vehicle crashes were initially considered; subsequently, casualties with missing data were excluded. Multiple logistic regression was estimated to explore the associations of potential risk factors with the likelihood of killed or seriously injured (KSI) casualties and to calculate adjusted odds ratios (AORs).

RESULTS

In total, 3,751,998 casualties from traffic accidents in the United Kingdom during 1990-2017 were included in the final data set; among these, 410,299 (10.9%) were KSI casualties, and 3,341,699 (89.1%) were slight injuries. Crashes on public holidays were 16% (AOR = 1.16; 95% confidence interval [CI] = 1.13-1.19) more likely to involve KSI casualties than were crashes on non-holidays. With other factors controlled for, crashes during the Queen's 2002 Golden Jubilee and on New Year's Day were 48% (AOR = 1.48; 95% CI = 1.06-2.07) and 36% (AOR = 1.36; 1.26-1.48) more likely to lead to KSIs, respectively.

CONCLUSIONS

The proportion of crashes resulting in KSI casualties on public holidays was higher than that on non-holidays. Furthermore, crashes during the Queen's 2002 Golden Jubilee had the highest risk of KSI casualties followed by New Year's Day.

A random parameter logistic model of fatigue-related motorcycle crash involvement in Hanoi, Vietnam

Since motorcycle taxi drivers often work long hours, fatigue would affect their riding abilities, impacting crash risks. However, there is limited understanding about motorcycle taxi drivers' fatigue-related crashes. This study investigates self-reported fatigue-related crashes among motorcycle taxi drivers in Hanoi, Vietnam. Results from a survey showed that approximately 16% of the motorcycle taxi drivers reported fatigue-related crash involvement. It was also found that nearly 37% of all crashes reported by motorcycle taxi drivers were related to fatigue while riding a motorcycle taxi. Results of the heterogeneity-in-means random parameter logistic model suggested that working fulltime, more delivery trips, and overweight conditions were associated with increased likelihoods of fatigue-related crash involvement. Hybrid taxi drivers, who operate as either traditional or ride-hailing taxi drivers at different times, and most ride-hailing taxi drivers had a reduced likelihood of fatigue-related crash involvement when compared to traditional taxi drivers. Overall, this study has revealed a significant issue of fatigue-related crashes among motorcycle taxi drivers. Immediate interventions via publicity or educational campaigns should be considered by authorities to address this important issue. Ride-hailing companies should contribute by sending warnings of excessive riding hours to ride-hailing taxi drivers.

Evaluating the combined effect of alcohol-involved and un-helmeted riding on motorcyclist fatalities in Taiwan

BACKGROUND

Alcohol-involved riders tend to engage in other risk-taking behaviours such as un-helmeted riding which could further increases injury severity. The combined effect of alcohol-involved and un-helmeted riding on fatal injuries is rarely investigated. This study investigated the interaction effect between blood alcohol concentration and helmet use on fatal injuries.

METHODS

This study used the National Taiwan Traffic Crash Dataset for the period from 2011 to 2015. Data on road crashes involving a motorcycle and an automobile were extracted and analysed. Multiple logistic regression models were used to calculate the adjusted odds ratio (AOR). We calculated an interaction effect for blood alcohol concentration and helmet use based on STROBE guidelines.

RESULTS

There were a total of 669,292 motorcyclist casualties; among these casualties, 3459 (0.5 %) motorcyclists sustained fatal injuries. Alcohol-involved riders were 9.47 times (AOR = 9.47; 95 % CI = 8.75-10.25) more likely than sober ones to sustain fatal injuries. Alcohol-involved and un-helmeted riders were approximately 18 times (AOR = 18.1; CI: 15.9-20.4) more likely to sustain fatal injuries than sober and helmeted riders. Riders involved in head-on crashes and approach-turn motorcycle crashes had an increased probability of sustaining fatal injuries by 240 % (AOR = 3.4; 95 % CI = 2.91-4.09) and 132 % (AOR = 2.3; 95 % CI = 2.016-2.67), respectively.

CONCLUSIONS

This study found that alcohol-involved riding acts synergistically with un-helmeted riding to increase motorcyclist injury severity.

Crash risk factors for novice motorcycle riders

BACKGROUND

Motorcycle riders have the highest injury and fatality rates among all road users. This research sought in-depth understanding of crash risk factors to help in developing targeted measures to reduce motorcycle crash injuries and fatalities.

METHODS

We used interview data from a study of 2,399 novice motorcycle riders in Victoria, Australia from 2010 to 2012 linked with their police-recorded crash and offence data. The outcome measure was self and/or police reported crash. The association between potential risk factors and crashes was explored in multivariable logistic regression models.

RESULTS

In the multivariable analysis, riders who reported being involved in three or more near crashes had 1.74 times (95% CI 1.11-2.74) higher odds of crashing compared to riders who reported no near-crash events, and riders who participated in a pre-learner course had 1.41 times higher odds of crashing (95% CI 1.07-1.87) compared with riders who did not attend a pre-learner course. Riders who had been involved in a crash before the study had 1.58 times (95% CI 1.14-2.19) higher odds of crashing during the study period compared with riders who were not involved in a crash. Each additional month of having held a license and learner permit decreased the odds of crashing by 2%, and each additional 1,000 km of riding before the study increased the odds of crashing by 2%.

CONCLUSION

Measures of pre-learner training and riding experience were the strongest predictors of crashing in this cohort of novice motorcycle riders. At the time of the study there was no compulsory rider training to obtain a learner permit in Victoria and no on-road courses were available. It may be plausible that riders who voluntarily participated in an unregulated pre-learner course became or remained at high risk of crash after obtaining a rider license. We suggest systematically reviewing the safety benefits of voluntary versus mandatory pre-learner and learner courses and the potential need to include on-road components.

Relationships between Body Mass Index and Self-Reported Motorcycle Crashes in Vietnam

The relationship between overweight, obesity, or body mass index (BMI) and crashes among drivers of passenger cars, vans, and trucks has been the focus of much research. However, little is understood about this relationship among motorcyclists, particularly motorcycle taxi drivers who tend to work long hours. Motorcycle taxis are an increasingly popular and important mode of travel in many cities, especially in South-East Asia, due partly to the rise of ride-hailing services. This paper assesses the body mass index (BMI) of motorcycle taxi drivers in Vietnam and its impacts on crashes among three types of drivers (traditional, ride-hailing, and hybrid). Data from a structured questionnaire survey of motorcycle taxi drivers conducted in Hanoi, Vietnam were used. Results show that 18.8% of motorcycle taxi drivers were overweight or obese whereas only 1.4% were underweight. Fulltime motorcycle taxi drivers were more likely to be overweight or obese. Results of random effect binary logistic regression show that overweight and obese motorcycle taxi drivers had significantly higher overall and injury crash risks, when compared to normal-weight motorcycle taxi drivers. Results also indicate that hybrid motorcycle taxi drivers had lower overall and injury crash risks when compared to traditional motorcycle taxi drivers.

Why is the rate of annual road fatalities increasing? A unit record analysis of New Zealand data (2010-2017)

INTRODUCTION

Recent increases in road crashes have reversed New Zealand's formerly declining crash rates to produce annual fatal and serious injury counts that are 49% higher than the lowest rates achieved in 2013.

METHOD

We model twenty-one factors in fatal and serious injury crashes, four years before and after 2013 using logistic regression. Three major factors are significantly different in the period after 2013, when crash rates increased: (1) alcohol as a cause, (2) learner licence holders, and (3) a regional effect for Auckland. Newly defined speed zones are a more common setting for crashes in the period of upturn but there is no coinciding elevated likelihood of 'speed as a causal factor'. Three factors related to road safety were less common: aged under 25-years old, fatigue, and not wearing a seatbelt.

RESULTS

Results are compared to rates of prosecutions for alcohol-related driving offences over this period. It is possible that New Zealand's successful road safety initiatives of the past have been undermined by reduced levels of enforcement and an unexpected outcome from the graduated driving licence system.

Evaluation of injuries sustained by motorcyclists in approach-turn crashes in Taiwan

OBJECTIVES

In western countries, a typical car-motorcycle crash occurs at an intersection where a car manoeuvres into the path of an oncoming motorcycle, which involves a car driver violates motorcycle's right of way (ROW). In Taiwan, however, a unique type of crash (approach-turn crash) occurs when a turning (including U-turn) motorcycle frequently infringes upon a car's ROW. The primary objective of this study was to examine injuries sustained by motorcyclists in this unique type of crash.

METHOD

Using the linked data from the National Taiwan Crash Database and the National Health Insurance Research Data from 2003 to 2015, this study examined several anatomical injuries (e.g., head and face, neck, chest and abdomen, spine, and lower extremities), as well as the resulting injury severity (e.g., death within 30 days, hospitalisation, and emergency visit only/outpatient, and length of hospital stay). Variables examined include demographic data (sex, age, alcohol use, license status, and helmet use), vehicle attributes (engine size, type of crash partner, and crash type), road and environmental factors (curvature, crash location, day of week and time of crash). Injuries sustained by motorcyclists in an approach-turn motorcycle-turning crash (motorcycle is a ROW violator) were compared with those sustained by motorcyclists in an approach-turn car-turning crash (car is the ROW violator).

RESULTS

A total of 21,919 motorcyclists were enrolled, of whom 18,041 and 3878 were motorcyclists involved in approach-turn car-turning and motorcycle-turning crashes, respectively. The percentage of death within 30 days; hospitalisation; length of hospital stay; and injuries to the head and face, neck, and chest and abdomen were significantly higher for motorcyclists in approach-turn motorcycle-turning crashes. Results of logistic regression models revealed that riding under the influence of alcohol and riding without a licence were associated with death/hospitalisation, and injuries to particular body regions (head and face, neck, and chest and abdomen). Helmet use was associated with a decreased likelihood of head and face and neck injuries.

CONCLUSION

Motorcyclists tended to be more severely or fatally injured and had increased head and face, neck, and chest and abdomen injuries when they were ROW violators than when their ROWs were violated at an intersection. Efforts to curb drunk riding and unlicensed riding may constitute effective intervention points.