The role of alcohol in Thailand motorcycle crashes

In order to identify motorcycle accident cause factors and countermeasures in Thailand, a large prospective study was undertaken. Researchers conducted on-scene, in-depth investigation and reconstruction of 969 collisions involving 1082 motorcycle riders. Accidents were randomly sampled and included all levels of injury severity. Alcohol proved to be the most outstanding cause factor, with 393 drinking riders in crashes. Alcohol accidents were distinctly different from non-alcohol crashes. Alcohol accidents were more frequent on weekends and particularly at night, usually when the rider was on his way home. Drinking riders were more likely to lose control of the motorcycle, usually by running off the road. They were more likely to be in a single vehicle accident, to violate traffic control signals, and to be in non-intersection collisions. Males were far more likely to drink and ride than females. Drinking riders were far more likely to be inattentive to the driving task just before they crashed, and to be the primary or sole cause of the accident. One-fourth of all riders did not go to the hospital, and another 42% needed only treatment in the emergency room. Drinking riders were more likely to be hospitalized and far more likely to be killed. The higher hospitalization and fatality rates of drinking riders resulted from the kinds of accidents in which they were involved, not from the minimal differences in speeds and helmet use. Problems with balance and coordination were about equally rare among drinking and non-drinking riders. Inattention was a far greater contributing factor.     

Examination of factors determining fault in two-vehicle motorcycle crashes

Motorcycle crashes frequently involve a combination of high-risk behaviors by the motorcyclist or the other crash-involved driver. Such behaviors may include riding or driving without appropriate licensure or while under the influence of alcohol, as well as deciding not to use a safety device such as a helmet or safety belt. Given that these factors frequently occur in combination with one another, it is difficult to untangle the specific effects of individual factors leading up to the crash outcome. This study assesses how various rider-, driver-, and other crash-specific factors contribute to at-fault status in two-vehicle motorcycle crashes, as well as how these same factors affect the propensity for other high-risk behaviors. Furthermore, the interrelationships among fault status and these other behaviors are also examined using a multivariate probit model. This model is developed using police-reported crash data for the years 2006–2010 from the State of Ohio. The results show that younger motorcyclists are more likely to be at-fault in the event of a collision, as are riders who are under the influence of alcohol, riding without insurance, or not wearing a helmet. Similarly, motorcyclists were less likely to be at-fault when the other driver was of younger age or was driving under the influence of alcohol, without insurance, or not wearing their safety belt. Crash-involved parties who engaged in one high-risk behavior were more likely to engage in other such behaviors, as well, and this finding was consistent for both motorcyclists and drivers. The results of this study suggest that educational and enforcement strategies aimed at addressing any one of these behaviors are likely to have tangential impacts on the other behaviors, as well.     

Analysis of fatal motorcycle crashes: crash typing

There were 2074 crashes fatal to a motorcycle driver in the United States during 1992. A computer program was developed to convert Fatal Accident Reporting System (FARS) data for these crashes into standard format English language “crash reports.” The computer generated reports were analyzed and crash type categories were defined. Five defined crash type categories accounted for 1785 (86%) of the 2074 crash events: Ran off-road (41%); ran traffic control (18%); oncoming or head-on (11%); left-turn oncoming (8%); and motorcyclist down (7%). Alcohol and excessive speed were common factors associated with motorcyclist crash involvement. Left turns and failure to yield were common factors associated with the involvement of other motorists. Suggested countermeasures include helmet use and enforcement of speed and impaired driving laws.     

A different perspective on conspicuity related motorcycle crashes

The most common type of conflict in which a motorcyclist is injured or killed is a collision between a motorcycle and a car, often in priority situations. Many studies on motorcycle safety focus on the question why car drivers fail to give priority and on the poor conspicuity of motorcycles. The concept of ‘looked-but-failed-to-see’ crashes is a recurring item. On the other hand, it is not entirely unexpected that motorcycles have many conflicts with cars; there simply are so many cars on the road. This paper tries to unravel whether – acknowledging the differences in exposure – car drivers indeed fail to yield for motorcycles more often than for other cars. For this purpose we compared the causes of crashes on intersections (e.g. failing to give priority, speeding, etc.) between different crash types (car–motorcycle or car–car). In addition, we compared the crash causes of dual drivers (i.e. car drivers who also have their motorcycle licence) with regular car drivers. Our crash analysis suggests that car drivers do not fail to give priority to motorcycles relatively more often than to another car when this car/motorcycle approaches from a perpendicular angle. There is only one priority situation where motorcycles seem to be at a disadvantage compared to cars. This is when a car makes a left turn, and fails to give priority to an oncoming motorcycle. This specific crash scenario occurs more often when the oncoming vehicle is a motorcycle than when it is a car. We did not find a significant difference between dual drivers and regular car drivers in how often they give priority to motorcycles compared to cars.     

How similar are two-unit bicycle and motorcycle crashes?

This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation.     

Applying Bayesian hierarchical models to examine motorcycle crashes at signalized intersections

Motorcycles are overrepresented in road traffic crashes and particularly vulnerable at signalized intersections. The objective of this study is to identify causal factors affecting the motorcycle crashes at both four-legged and T signalized intersections. Treating the data in time-series cross-section panels, this study explores different Hierarchical Poisson models and found that the model allowing autoregressive lag-1 dependence specification in the error term is the most suitable. Results show that the number of lanes at the four-legged signalized intersections significantly increases motorcycle crashes largely because of the higher exposure resulting from higher motorcycle accumulation at the stop line. Furthermore, the presence of a wide median and an uncontrolled left-turn lane at major roadways of four-legged intersections exacerbate this potential hazard. For T signalized intersections, the presence of exclusive right-turn lane at both major and minor roadways and an uncontrolled left-turn lane at major roadways increases motorcycle crashes. Motorcycle crashes increase on high-speed roadways because they are more vulnerable and less likely to react in time during conflicts. The presence of red light cameras reduces motorcycle crashes significantly for both four-legged and T intersections. With the red light camera, motorcycles are less exposed to conflicts because it is observed that they are more disciplined in queuing at the stop line and less likely to jump start at the start of green.     

Trends in deaths due to motorcycle crashes and risk factors in injury collisions

In the past 25 years, the numbers of registered motorcycles in the United States and California have increased about 1000 and 1100%, respectively. In the same period, the motorcycle collision death rate per million population more than doubled. The purposes of the study were to examine time trends in deaths due to motorcycle collisions, examine a methodologic problem in the study of motor vehicle collision death rates, and to determine driver and vehicle factors which may discriminate in the production of motorcycle crash related injurites.

With the exception of 1974, the increase in the ratio of registered motorcycles per 100,000 population in the United States corresponded to an increase in the crude death rate per million population. A similar pattern was also found in California.

Stepwise discriminant analysis was used to determine an optimum set of factors associated with motorcycle collision injuries. The analysis indicated that for male drivers age was the single factor most significantly related to motorcycle collision injuries. Other factors, in addition to age, which added to the power of the discrimination included number of prior motorcycle driving violations, frequency of motorcycle use, number of prior motorcycle crashes, motorcycle drivers' training, and height of the drivers.     

Characteristics of fatal motorcycle crashes into roadside safety barriers in Australia and New Zealand

This paper reports on the findings of a retrospective case series study of fatal motorcyclist–roadside barrier collisions. Cases were retrieved from the National Coroners Information System (NCIS), the coronial case files of Australian jurisdictions, and the Crash Analysis System (CAS) of the New Zealand Transport Agency. Seventy seven (77) motorcycle fatalities involving a roadside barrier in Australia and New Zealand were examined. The fatalities usually involved a single vehicle crash and young men. The roadside barriers predominantly involved were steel W-beams, typically on a bend in the horizontal alignment of the road. A majority of fatalities occurred on a weekend, during daylight hours, on clear days with dry road surface conditions indicating predominantly recreational riding. Speeding and driving with a blood alcohol level higher than the legal limit contributed to a significant number of these fatalities.     

A longitudinal study of risk factors for motorcycle crashes among junior college students in Taiwan

A cohort of 4729 junior college students in an urban and a rural area in Taiwan was followed up for a period of 20 months. Students' characteristics, including riding exposures, as well as human, vehicular, and environmental factors were collected using one initial and three follow-up questionnaires. The Anderson-Gill (AG) multiplicative intensity model was used to determine the risk of a motorcycle crash over time while also allowing for the modeling of multiple events. The average response rate for the four assessments was 92%. The adjusted relative hazard (RH) for students living in the rural as opposed to the urban area for crashes was 1.67 at the beginning of the study but decreased to 0.66 by the end. Past motorcycle crash history, number of riding days, average riding distance, risk-taking level, alcohol consumption, and traffic violations were all significantly associated with an increased risk of being involved in a crash. Conversely, increasing age, riding experience, and automobile licensure were related to a decreased risk of crashing. Furthermore, helmet use was not independently related to the risk of crashing. In conclusion, a high-risk group predisposed to involvement in a motorcycle crash, including both non-injury and injury-related crashes, can be identified using selected risk factors for crash prevention among young riders.     

Severity of disability related to road traffic crashes in the Spanish adult population

BackgroundThe severity of disability related to road traffic crashes has been little studied, despite the significant health and socio-economic impacts that determine victims’ quality of life.ObjectiveTo estimate the consequences of road traffic crashes on the severity of disability, in terms of individuals’ capacity to execute activities and perform tasks in their current environment, using aids.MethodsCross-sectional study conducted on community-dwelling participants in the “2008 National Survey of Disability”, with data on 91,846 households having 20,425 disabled persons, 443 of whom had disability due to road traffic crashes. We measured severity using two indicators, i.e., the Capacity (CSI) and Performance (PSI) Severity Indices.ResultsThe highest proportion of disability was mild (CSI = 70.5%; PSI = 80.8%), while 7.6% (CSI) and 4.9% (PSI) was severe/complete respectively. The moderate/severe disability rate was 0.6 per thousand on the CSI, decreasing to 0.4 per thousand on the PSI. No differences were observed by age or sex. Moderate/severely disabled persons had a fourfold higher probability of being retired or unfit for work. Mental and nervous system impairments were more closely related to moderate/severe/complete problems of capacity and performance (p < 0.001), disability for carrying out general tasks and demands, and interpersonal interactions and relationships (p < 0.001). Being permanently bedridden (p < 0.001), receiving aids (p < 0.001), family support (p < 0.05) and moving home (p < 0.05) increased with an increase in the level of severity.ConclusionRoad traffic crashes mainly cause mild disability. Moderate/severe disability is associated with lower work capacity, greater functional dependence, and increased need of aids, moving home and family support.     

Travel exposure and choice of comparison crashes for examining motorcycle conspicuity by analysis of crash data.

Much research has been conducted examining the problem of motorcycle road crashes. Most of this research has concluded that motorcyclists have a conspicuity problem, particularly during the day. This type of research has often involved comparing multi-vehicle motorcycle crashes with single vehicle motorcycle crashes occurring during the day and night. The aim of this paper is to point out that comparison of single and multiple vehicle motorcycle crashes juxtaposes subsets of crashes with clearly different causes (car drivers' possible failure to detect a motorcyclist against motorcyclists' loss of vehicle control). Comparing groups of crashes for which conspicuity can be posited as a common cause (car drivers' possible failure to detect a motorcyclist or car) may be a more enlightening comparison. The issue of exposure is also examined in this paper.     

Severity of driver injury and vehicle damage in traffic crashes at intersections: a Bayesian hierarchical analysis

Most crash severity studies ignored severity correlations between driver-vehicle units involved in the same crashes. Models without accounting for these within-crash correlations will result in biased estimates in the factor effects. This study developed a Bayesian hierarchical binomial logistic model to identify the significant factors affecting the severity level of driver injury and vehicle damage in traffic crashes at signalized intersections. Crash data in Singapore were employed to calibrate the model. Model fitness assessment and comparison using intra-class correlation coefficient (ICC) and deviance information criterion (DIC) ensured the suitability of introducing the crash-level random effects. Crashes occurring in peak time and in good street-lighting condition as well as those involving pedestrian injuries tend to be less severe. But crashes that occur in night time, at T/Y type intersections, and on right-most lane, as well as those that occur in intersections where red light cameras are installed tend to be more severe. Moreover, heavy vehicles have a better resistance on severe crash and thus induce less severe injuries, while crashes involving two-wheel vehicles, young or aged drivers, and the involvement of offending party are more likely to result in severe injuries.     

Correlates of motorcycle helmet use among recent graduates of a motorcycle training course

Helmets significantly decrease morbidity and mortality from motorcycle crashes, but many areas of the world lack universal helmet laws. To educate motorcyclists in areas without helmet laws, more knowledge of motorcyclists’ helmet beliefs is needed.A web-based survey was therefore designed to assess motorcyclists’ attitudes, norms and behaviors towards helmets in a U.S. state with a limited helmet law. Of 445 survey respondents, 68.4% of respondents reported always wearing a helmet. The not-always-helmeted riders were more likely than the always-helmeted to be male; to bave less education; and to have a history of previous motorcycle crashes and injuries. Although both groups had taken rider training classes, fewer of the not-always-helmeted had learned how to ride in a class. The strongest correlates of being not-always-helmeted (vs. always-helmeted) were attitudes that helmets were not protective and impaired sight/hearing; and the normative belief that they would only wear helmets if forced by law. Because attitudes are often more easily changed than normative beliefs, education may increase helmet use. However, less than half of riders in this state with a mandatory education program learned how to ride from a rider education course, and 44% of non-helmeted said they would only wear a helmet if forced by law. Legislation may therefore be a more efficient and effective strategy than education to increase helmet use.     

Methodological issues in motorcycle injury epidemiology

Motorcycle riders are over 30 times more likely than car occupants to die in a traffic crash. While this fact is well known, specific issues of methodology in epidemiological motorcycle-injury research have been rarely researched. To facilitate more-valid research on motorcycle injuries, this article evaluates the current state of our knowledge on how we measure the population at risk of injury, completeness of case finding and identification, validity of crash/injury data sources, and completeness of information on important exposures such as alcohol consumption, helmet status, crash severity, and crash speeds, as well as problems of existing injury severity scales and statistical analyses for correlated injury data.     

Road crashes involving animals in Australia

Each year in Australia many thousands of collisions occur between motor vehicles and animals, resulting in considerable vehicle repair costs, injury to persons, and loss of animal life. This paper reviews animal-related road crashes in Australia and presents data from the in-depth Rural and Remote Road Safety Study in North Queensland for serious casualties (n = 33) resulting from direct impact with an animal or swerving to avoid an animal on public roads. These crash types accounted for 5.5% of all eligible on-road serious casualties in the study and, hence, are considered to be an important issue that requires particular attention within rural and remote areas. Kangaroos and wallabies were the predominant species involved in these crashes (44.8%). Consistent with international studies, night-time travel was found to be a significant risk factor when comparing animal-related crashes to other serious injury crashes in the study. There were also a significantly higher proportion of motorcyclists (51.7%) than other vehicle occupants involved in animal-related serious crashes compared to all other serious injury crashes. Data matching to official Government records found underreporting of animal-related crashes to be an issue of concern. These findings are discussed in terms of countermeasures suitable for the Australian context and the need for consistent crash reporting across jurisdictions.     

Issues in motorcycle sensory and cognitive conspicuity: The impact of motorcycle low-beam headlights and riding experience on drivers’ decisions to turn across the path of a motorcycle

Background

Crashes involving a passenger car and a motorcycle, where the car is turning across the path of the motorcycle, are a major crash type of motorcycle riders. It has been proposed that the incidence of such crashes could be reduced through improvements in motorcycle conspicuity. Operation of low-beam headlights on motorcycles has been discussed as one approach for improving the “sensory conspicuity” of motorcycles during daylight hours, whilst previous experience as a rider may serve to heighten “cognitive conspicuity” through raised awareness of motorcyclists on our roads.

Method

Twenty-three experienced car drivers with no riding experience (“drivers”) and 20 experienced car drivers who were also motorcycle riders (“driver–riders”) completed a series of trials in a driving simulator where their task in each trial was to turn ahead of an oncoming vehicle if they felt that they had sufficient room to do so safely. A key manipulation across trials was whether the oncoming vehicle was a motorcycle with headlights on, or a motorcycle with headlights off. Time gap (short, medium, long) was also manipulated.

Results

Results indicate that, at time gaps defined in the current study as short, low-beam headlights may confer some benefit in gap acceptance by encouraging drivers to accept fewer gaps ahead of a motorcycle with headlights on than ahead of a motorcycle with headlights off. No statistically significant differences in gap acceptance between the headlight conditions were found at either the medium or long time gaps. Irrespective of time gap, driver–riders were found to adopt a more efficient turn strategy than drivers with no direct riding experience.

Conclusions

Overall, the present research provides support for the use of low-beam headlights and riding experience as tools through which to augment the sensory and cognitive conspicuity of motorcycles, respectively. It is proposed that further research aim to explore directly the precise mechanisms underlying the observed effects.     

Helmet use and motorcycle fatalities in Taiwan

Motorcycle deaths accounted for more than half of total traffic fatalities in Taiwan in 2002. This study uses the police-reported crash data from Taiwan between 1999 and 2001 to estimate the effectiveness of helmets, simultaneously taking into account of sample selection bias. Sample selection arises because helmet usage will affect the probability of death or injury, which in turn influences whether a crash is included in the data. The results show that sample selection does not seriously bias the estimate of helmet effectiveness and helmets reduce the probability of death in a crash by 40%, which is higher than what was previously found. Without helmets, the number of motorcyclists killed in 2001 would have jumped by 51%. The estimated proportion of helmeted motorcyclists has increased from 71 to 78% between 1999 and 2001, suggesting that helmet use is rising after the implementation of mandatory helmet law in 1997. Also, helmets significantly reduce the likelihood of head and neck injuries in a crash by 53%, and lead to a 71% reduction in the probability of death caused by head and neck injuries.     

Alcohol use and motorcycle accidents

An investigation of 1508 of the 1577 fatal and injury producing motorcycle accidents reported to Victoria police during 1974 revealed that alcohol usage was a significant factor. A similar result was indicated by five other Australian studies which report on post-mortem examinations of fatally injured motorcycle riders. Alcohol affected riders were significantly over represented in fatal and single vehicle accidents. The majority of killed riders had blood alcohol levels typical of problem drinkers. Motorcycle riders had similar blood alcohol levels to a comparable group of drinking car drivers but a significantly lower proportion of killed motorcycle riders were affected by alcohol than killed car drivers. Motorcycle riders affected by alcohol were mainly younger than twenty-five years of age, but this was probably due to the youthfulness of the motorcycle riding population.     

Evaluation of the motorcycle rider course

A sample of 516 persons who had taken the Motorcycle Safety Foundation's motorcycle rider course within the prior three years and a control group who had not taken the course completed a questionnaire about their riding exposure, violations and accidents, as a means of evaluating the effects of the course. The major findings were: (a) when controlling for age and years licensed, those who took the course did not have a lower accident rate than the control group; (b) there were no differences in the violation rates between the groups; (c) the cost of damage to the motorcycles per million miles was not less for those who took the course; and (d) the estimated cost of medical treatment of injuries per million miles was not significantly less for the group which took the course; but, (e) the mean cost of damage to the motorcycles was less for those who took the course; and (f) the mean medical cost per accident was less among those who took the course than the control group. The latter may be attributable to the finding that (g) those who took the course made more use of protective clothing, such as helmets, than the control group, and to other exposure factors affecting the severity of the accidents.     

Visual assessment of pedestrian crashes

Of the numerous factors that play a role in fatal pedestrian collisions, the time of day, day of the week, and time of year can be significant determinants. More than 60% of all pedestrian collisions in 2007 occurred at night, despite the presumed decrease in both pedestrian and automobile exposure during the night. Although this trend is partially explained by factors such as fatigue and alcohol consumption, prior analysis of the Fatality Analysis Reporting System database suggests that pedestrian fatalities increase as light decreases after controlling for other factors.This study applies graphical cross-tabulation, a novel visual assessment approach, to explore the relationships among collision variables. The results reveal that twilight and the first hour of darkness typically observe the greatest frequency of pedestrian fatal collisions. These hours are not necessarily the most risky on a per mile travelled basis, however, because pedestrian volumes are often still high. Additional analysis is needed to quantify the extent to which pedestrian exposure (walking/crossing activity) in these time periods plays a role in pedestrian crash involvement. Weekly patterns of pedestrian fatal collisions vary by time of year due to the seasonal changes in sunset time. In December, collisions are concentrated around twilight and the first hour of darkness throughout the week while, in June, collisions are most heavily concentrated around twilight and the first hours of darkness on Friday and Saturday. Friday and Saturday nights in June may be the most dangerous times for pedestrians. Knowing when pedestrian risk is highest is critically important for formulating effective mitigation strategies and for efficiently investing safety funds. This applied visual approach is a helpful tool for researchers intending to communicate with policy-makers and to identify relationships that can then be tested with more sophisticated statistical tools.