Road traffic suicides

Unlocking the Narrative: Using Text Mining to Reveal the Hidden Factors behind Suicide Related Traffic Crashes

Suicide is the deliberate act of ending a person's own life due to multifarious reasons. In the U.S., suicide is the 10th major cause of death. Nearly 45,000 people died by suicide in 2016 across the nation. It is anticipated that not all traffic crashes can be considered as accidents. Traffic crash related injuries are occasionally considered a means of suicide, and some crashes occur due to the suicidal attempts. These attempts can be made by operators of motor vehicles, jumpers into the pathway of trains, and pedestrians deliberately jumping into the vehicle trajectory. There are a handful of studies that have focused on traffic crashes (both railroad and roadway) related to suicidal incidents. This study aimed to explore the insights associated with suicide related traffic crashes (SRTCs) by collecting traffic data for seven years (2010-2016) from Louisiana. At first, exploratory data analysis was performed to examine the five Ws (who, what, why, when, and where) associated with SRTCs. Later, this study applied text network analysis, which was not performed in any of the previous studies, to provide additional contexts of these crashes. The findings of this study can shed lights on an unexplored arena of transportation safety research.

Road vehicle collision suicide in Australia: Trends, collision types, and individual characteristics

BACKGROUND

Suicide by road vehicle collision in Australia is under-explored with mixed findings. We aimed to address this research gap by examining time trends, different types of vehicle collision, and individual characteristics related to vehicle-collision suicide.

METHOD

We retrospectively analyzed deaths by suicide between 1st January 2001 and 31st December 2017 in Australia, using coronial records from the National Coronial Information System. The travel mode used and collision counterpart were retrieved from records of death by vehicle-collision suicide using all available information. We conducted negative binomial regression analysis to examine annual changes in suicide rate by vehicle collision on a public road (N = 640) and other methods of suicide (N = 41,890), and logistic regression analysis to examine individual characteristics associated with the likelihood of dying by suicide via road vehicle collision.

RESULTS

Overall, the national suicide rate involving road vehicle collision significantly increased, while the rate by other methods significantly decreased. Drivers accounted for 61% of suicide events by vehicle collision, of which 72% were single-vehicle collisions (commonly involving a tree). For multiple-vehicle collision suicide events, 82% involved collision with a truck. Pedestrians accounted for more than one-third of suicide events, of which 58% involved collision with a truck and 23% involved collision with a car/van. Individuals who were male (odds ratio 1.15; 95% CI 0.88-1.50), aged <25 years old (odds ratio 5.27; 95% CI 3.05-9.10), non-Indigenous (odds ratio 3.36; 95% CI 1.71-6.62), and born overseas (odds ratio 1.40; 95% CI 1.10-1.79) were more likely to die by vehicle-collision suicide than by other methods of suicide.

CONCLUSIONS

This study provides a better understanding of road vehicle collision suicide in Australia and informs future research directions on topic. Our findings can be used to inform suicide prevention initiatives to reduce vehicle-collision suicide deaths.

What triggers road traffic fatalities among older adult drivers? An investigation based on the Swedish register for in-depth studies of fatal crashes

INTRODUCTION

Road traffic fatalities among drivers result not only from erroneous driving manoeuvres. They can also be triggered by poor mental or physical health like suicidal acts and acute disease attacks, the latter being more frequent with age. There are few studies comprising all the different triggers of fatal crashes among older drivers and on how these triggers evolve over time. This Swedish national study aims to investigate this, considering drivers 50+ years.

METHOD

For the period 2010-2019, data on non-commercial car drivers aged 50 and older were extracted from the Swedish Transport Administration's in-depth studies of fatal crashes, compiled in a register encompassing all road traffic fatalities. The crash triggers reported were classified as suicide, acute disease, own manoeuvre (single or other type of crash), external, and undetermined. Total and annual frequencies were presented by crash trigger, overall and stratified by sex and age groups.

RESULTS

In total, 762 fatalities were identified and with 709 of them, it was possible to classify the crash trigger: 12% resulting from suicide; 29% from acute disease; 49% from the driver's own manoeuvre; and 10% from an external crash trigger. Suicides increased from 9% in average 2010-2014 to 15% in 2015-2019 while acute disease decreased (from 32% to 27%). The overall male-to-female ratio was 4.5, and as high as 8.7 for acute disease. The relative importance of each trigger varied with age with, for instance, acute disease being more frequent in the two younger age groups; 31% for 50-64 and 52% for 65-79 years old drivers, while own manoeuvre was more prominent for drivers aged 80 and older (23%).

CONCLUSION

The distribution of the four different triggers of road traffic fatalities varies only slightly over time and, a majority are triggered by the driver's own manoeuvre. However, a substantial proportion, about four out of ten,are triggered by a health condition, of which some are suicide but the major part an acute disease, mainly cardiovascular. In some instances, such crashes can be harmful to other road users. Having in mind the need for safety and mobility of older drivers and the protection of all road users, there is a need for the promotion of road safety policies that encompass a wider range of measures to help reducing the likelihood of fatal and severe crashes to happen e.g., targeting incapacitated drivers.

An overview of suicides related to motor vehicles

Although vehicles may be used in a wide variety of suicides, this has not been a focus in the forensic literature. Thus, an analysis of coronial autopsy reports at Forensic Science SA, Adelaide, South Australia over a 16-year period from January 2005 to December 2020 was undertaken to provide an overview of cases in which it was considered that a vehicle had been integral to the successful completion of a suicide. De-identified details were collected from all cases in which a vehicle had facilitated or been used as a method of suicide. A number of different types of vehicle-related suicide methods were identified, including cases where vehicles had been used as secure places for suicide or where the vehicle had been used to cause significant blunt force trauma or to enter a lethal environment such as water. Specific examples were taken from the following categories: (1) inhalation of gas, (2) drug toxicity, (3) hanging or ligature strangulation, (4) self-immolation, (5) drowning, (6) vehicle collision, (7) driving off a cliff, (8) jumping or lying in front of a vehicle and (9) the use of more than one method (i.e. complex). This report is not intended to provide an epidemiological analysis of car-related suicides. Instead, the details of selected cases have been used to illustrate the spectrum of methods that may be used in vehicle-assisted suicides.

Characteristics of suicide-related crashes and their potential interventions: A literature review

OBJECTIVE

To develop countermeasures to decrease road trauma, it is essential to increase our understanding of fatal and injury crashes with suicidal intent. As suicide-related crashes can be difficult to identify it seems likely suicide-related road fatalities and injuries are under-reported. Under-reported crashes may lead to two policy issues: these types of casualty crashes may not receive adequate funding for countermeasure development and implementation due to not having a sufficient evidence-basis to justify allocation of resources, and may be miscategorized as having other factors contributing to the crashes, thus resources may be incorrectly allocated to countermeasures to address these other factors. This paper seeks to develop and document characteristics and potential countermeasures to identify and prevent such crashes.

METHODS

Two literature reviews of peer-reviewed journal manuscripts were performed to identify suicide-crash characteristics and potential countermeasures and strategies. Of 61 peer-reviewed journal manuscripts identified from the literature searches, 17 manuscripts fit the criteria and were reviewed. Information regarding the characteristics of suicide-related crashes, as well as potential strategies and countermeasures were gleaned from these manuscripts.

RESULTS

A list of characteristics was developed, underpinning development of a methodology to identify these types of crashes. Strategies and countermeasures recommended by international (road-) agencies to identify and prevent suicide-related crashes were documented and discussed.

CONCLUSION

As suicide-related crashes almost always take place in public space, the grief and pain resulting from such crashes not only relates to the victim, the people who knew the victim, but in many cases also involve the general public. It is therefore paramount to start the discussion about suicide-related crashes to increase awareness, increase willingness to establish a reliable data and knowledge base, and encourage help seeking in individuals at increased risk of attempting suicide using this method.

Self-harm on roads: Register-based study of methods and characteristics of individuals involved

BACKGROUND

Suicide on roads is receiving increased attention. However, there has been little research on non-fatal road-related self-harm. This study was conducted in order to investigate the characteristics of such acts.

METHOD

Information on non-fatal road self-harm was extracted from a self-harm monitoring system database of self-harm presentations to a major general hospital in England during 2005-2017. Patients were identified through being referred for psychosocial assessment by a clinical service and through scrutiny of medical records.

RESULTS

During the 13-year study period 110 individuals (67 males, 43 females) presented to the hospital with road-related self-harm: 38 (34.5%) jumped from bridges, 34 (30.9%) jumped or lay in front of vehicles, 27 (24.5%) crashed vehicles and 11 (10.0%) jumped from moving vehicles. Crashing vehicles was more common in males and jumping from vehicles more common in females. In patients who received a psychosocial assessment, their most frequent problems were with a partner, employment and family members. Over half had been in psychiatric care and nearly two-thirds had a history of previous self-harm. Suicide intent was often high, especially in those who crashed a vehicle or jumped from a bridge.

LIMITATION

The study was based on presentations to a single hospital. Some data were not available for non-assessed patients.

CONCLUSIONS

Road-related self-harm, while not common, more frequently involves males and the acts are often of high suicidal intent. The range of problems preceding this method of self-harm indicates that there needs to be a variety of aftercare interventions, adapted to each individual's situation.

Means restriction for the prevention of suicide on roads

BACKGROUND

Road traffic suicides are common. However, due to the difficulty in distinguishing between motor vehicle crash fatalities and actual suicides, no official figures exist for this method of suicide. Restricting access to means is an important universal or population-based approach to suicide prevention with clear evidence of its effectiveness. However, the evidence with respect to means restriction for the prevention of suicide on roads is not well established. We conducted a systematic review to assess the impact of restrictions on the availability of, or access to, means of suicide on roads.

OBJECTIVES

To evaluate the effectiveness of interventions to restrict the availability of, or access to, means of suicide on roads.

SEARCH METHODS

We searched the Cochrane Library, MEDLINE, Embase, PsycINFO, and the Transport Research International Documentation (TRID) Database from the date of database inception to March 2020. We conducted searches of the World Health Organization International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov to identify unpublished and ongoing studies. We applied no date, language, or publication status restrictions to these searches.

SELECTION CRITERIA

Eligible studies were randomised or quasi-randomised controlled trials, controlled intervention studies without randomisation, before-after studies, or studies using interrupted time series designs, which evaluated interventions to restrict the availability of, or access to, means of suicide on roads.

DATA COLLECTION AND ANALYSIS

Two review authors screened abstracts and full-text publications against the inclusion criteria. Two review authors planned to independently extract data and assess risk of bias of included studies. However, we identified no studies eligible for inclusion.

MAIN RESULTS

We identified no studies that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

This systematic review highlights the paucity of research around road traffic suicides and the need for future robust studies that aim to investigate the effectiveness of interventions to prevent suicide on roads. Suicide ascertainment is a key issue; therefore, clear objective criteria are necessary in order to scale up and study this method more accurately. In the absence of any substantial evidence, we advocate for more awareness on road traffic suicides and its inclusion in future government suicide prevention policies. Further research exploring effective measures, particularly those that do not require driver compliance, are also needed.

Lying on the Road Before Being Run Over: Vehicular Manslaughter, Suicide, or Accident? Two Case Reports and Literature Review

We present two apparent hit-and-run cases where two women were run over. The vehicles involved were subsequently traced and their owners charged with manslaughter. Autopsy evidence, scientific investigation of the scene and circumstances of the deaths, technical inspection of the vehicles, and DNA analysis strongly suggested that both victims were lying on the road before the accident. Case 1 was a suicide. In Case 2, the victim had fallen to the ground following acute alcohol intoxication. Victimological analysis was pivotal in reconstructing the dynamics of the events. We suggest that a hit-and-run fatality should not be regarded as a manslaughter case until each piece of evidence has been carefully considered. We also propose an interdisciplinary method of reconstructing run over occurrences based on the following three steps: (i) identify whether there was a primary impact when the victim was in an upright position; (ii) identify victim drug/alcohol intoxication and/or presence of acute or chronic disease or injury, which may have contributed to the impact; and (iii) consider suicide intent.

Educational inequalities in traffic deaths during fluctuations of the economy in four Argentinian provinces, 1999-2013

OBJECTIVES

The objective of this study is to analyse how educational differentials in traffic mortality changed during economic fluctuations in four Argentinian provinces.

STUDY DESIGN

Retrospective quantitative analysis of secondary data.

METHODS

Data on fatalities due to traffic injuries (all traffic injuries, pedestrians/cyclists, motorcyclists, car users and unspecified road users) in four Argentinian provinces between 1999 and 2013 were linked to population data and information on the educational level of the deceased to compute mortality rates by educational level. Negative binomial models were estimated using age, sex, year, province of residence, year of economic expansion or recession and educational level as explanatory variables.

RESULTS

Annual traffic mortality differentials by educational level were lower during the period of economic crisis. An absolute increase in traffic mortality was observed in individuals of low educational level during economic expansions, but here, there were no traffic mortality differences for individuals of medium to high educational level. The educational gap in motorcyclist mortality widened during the period of quick economic expansion between 2005 and 2013.

CONCLUSIONS

We found less educational inequality in traffic mortality during an economic crisis in a developing country. However, the educational inequalities for different subtypes of traffic mortality show different patterns of evolution during the cycle of economic expansion and recession. Considering deaths due to traffic injuries, economic growth seems to be riskier for individuals of lower educational level compared with those of medium-high educational level.

The significance of preexisting medical conditions, alcohol/drug use and suicidal behavior for drivers in fatal motor vehicle crashes: a retrospective autopsy study

Driver fatalities in motor vehicle collisions (MVCs) encompass accidents, suicides, and natural deaths when driving. The objective of this study was to determine the significance of pathology and other autopsy findings for drivers in fatal MVCs. Forensic autopsy records of driver fatalities in southeast Norway between 2000 and 2014 were studied retrospectively. Data from individual police and collision investigation reports were also collected and analyzed. In 406 driver fatalities, the male/female ratio was 340/66; 9% died from natural causes, 9% were suicides, 65% were culpable accidental deaths, 14% were nonculpable deaths, and 3% were undetermined deaths. Head injuries and thoracic injuries were the most common causes of death. A seatbelt had been worn in 50% of the fatalities, and its prevalence did not differ between accidental deaths and suicides. Blood levels of alcohol and/or drugs that indicated impairment at the time of the collision were found in 40% (105/262) of all culpable accidental deaths but in 50% (64/127) of drivers aged up to 35 years. Pathology (most often cardiovascular disease) suggestive of sudden incapacitation before the collision was present in 24% (62/264) of drivers who were culpable in the accident and in 70% (46/66) of culpable drivers older than 55 years. A substantial proportion of drivers are killed in accidental collisions that may have occurred as a result of either alcohol/drug impairment or preexisting disease. Suicides and natural deaths both constitute significant proportions of MVC fatalities and may be misclassified unless a full inquest including an autopsy is performed.

Sex differences in suicides among children and youth: the potential impact of misclassification

OBJECTIVES

We examined whether established sex differences in suicide rates persist when adjustments are made for potential misclassification of deaths in children and youth.

METHODS

This is a retrospective, descriptive study of 1294 suicides, 961 accidental and 254 undetermined deaths occurring between January 1, 2000 and December 31, 2007, among persons aged 10 to 25 years in Ontario, Canada. Using data from Coroner's records, causes of death were reclassified based on two different misclassification criteria. Actual and reclassified suicide rates were calculated by sex and age group (with 95% confidence intervals) and by year of death.

RESULTS

Males aged 16-25 years accounted for the majority of suicides (68.9%). Asphyxia was the most common cause of suicide in both sexes. While suicides by shooting were almost exclusive to males, suicides due to alcohol/drug toxicity were significantly higher in females. Both before and after reclassification of suicide deaths, sex differences in suicide rates emerged in the 16-25 years age group. In each study year, both actual and reclassified suicide rates were higher in males than females.

CONCLUSIONS

Sex differences in suicide rates emerging in adolescence are unlikely to be due to misclassification. Other proposed explanations for sex differences in youth suicide rates should be investigated further.

Car accidents as a method of suicide: a comprehensive overview

The research literature provides evidence on the possible link between single-car accident drivers and suicidal intent, and some scholars have stressed the role of unconscious suicidal motivations in some single-car accidents. This paper review relevant literature on the topic and sheds light on neglected factors that may play a central role in reducing the number of deaths due to car accidents. We performed careful PubMed, and PsycInfo searches to identify all papers and book chapters in English during the period 1955-2011. Our overview of the literature indicates that above 2% of the traffic accidents are suicide behaviors. However, the phenomenon may be underreported, considering that suicides by car accidents may be reported as accidental in the national statistics. On the other hand, the association between accident-pronesses and unconscious self-destructive impulses is an issue that is difficult to solve.

Suicide by motor vehicle "accident" in Queensland

OBJECTIVE

Around the world, a substantial proportion of motor vehicle crash deaths are recognized as "hidden" suicides. This project sought to progress understandings of drivers who used a motor vehicle to die by suicide in Queensland, Australia, during the period 1990 to 2007.

METHODS

Data for this study were derived from the Queensland Suicide Register and forensic crash investigation case records. Analysis focused on life circumstances and events preceding the death, physical and mental illnesses, past suicidality, and indication of suicide intent (e.g., suicide notes or statements).

RESULTS

Compared to cases using other methods, confirmed driver suicides were more likely to be males aged between 25 and 44 years who were employed at the time of death. A large proportion of driver suicides had consumed alcohol immediately prior to the crash and experienced a number of life events, including relationship conflict, legal or criminal issues, and financial problems.

CONCLUSION

These exploratory results indicate the need to educate crash investigators about the characteristics of those who use a motor vehicle to die. Improving the information available on the mental and physical health and background life-related factors of crash victims can help coroners and researchers determine whether these deaths were intentional. Further investigation is needed in order to formulate intervention strategies for those who may be vulnerable to driver suicide.

Suicide of a cyclist

The rate of suicides in road traffic fatalities is estimated at 1-8% depending on the investigated study material. Especially single-car accidents, for which no technical reason or driving error is apparent, are considered suspicious. The elucidation of suicides in road traffic is difficult if there are no relevant clues such as the announcement of suicide plans shortly before the event or a suicide note. Individuals who intentionally kill themselves in road traffic often have a history of mental illness. The authors report on a suicide using a bicycle. A 71-year-old man intentionally drove into the wall of a house situated at the end of a hill road and suffered an open craniocerebral trauma and an aortic rupture. The pattern of findings and the circumstances of the case are described.

Unusual methods of suicide: complexities in investigation

Differentiation between suicide and homicide often becomes difficult owing to the unusual methods of suicide used by the victim and the complexities thus posed. Investigating the cases of unusual suicides provides a considerable challenge to the authorities concerned. The issue of homicide should often be ruled out in such cases, which require careful evaluation. This is best done by correlating the morbid anatomical findings at autopsy with the death scene analysis coupled with psychological autopsy. Many forensic practitioners have reported unusual methods of suicide at their respective workplaces. Various types of unusual methods of suicide and the complexities involved in their investigation are presented and discussed.