Raphael H. Grzebieta

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.

Injury typology of fatal motorcycle collisions with roadside barriers in Australia and New Zealand

Motorcyclists contribute significantly to road trauma around the world through the high incidence of serious injuries and fatalities. The role of roadside safety barriers in such trauma is an area of growing concern amongst motorcyclists, road authorities and road safety researchers and advocates. This paper presents a case series analysis of motorcyclists that were fatally injured following a collision with a roadside barrier during the period 2001-2006 in Australia and New Zealand. Injury profiles and severities are detailed, and associations with crash characteristics are investigated. It is shown that the thorax region had the highest incidence of injury and the highest incidence of maximum injury in fatal motorcycle-barrier crashes, followed by the head region. This is in contrast to fatal motorcycle crashes in all single- and multi-vehicle crash modes, where head injury predominates. The injury profiles of motorcyclists that slid into barriers and those that collided with barriers in the upright posture were similar. However, those that slid in were more likely to receive thorax and pelvis injuries.

Head and neck responses in oblique motorcycle helmet impacts: a novel laboratory test method

The dynamics of a Hybrid III dummys head and neck in helmeted impacts using a novel oblique impact test were studied. Three impact conditions were investigated that simulated a range of motorcyclist head impacts and provided estimates of head and neck injury using published injury assessment reference values. The resultant linear and angular accelerations in the coronal plane were significantly higher for an impact to the side of the head when compared with frontal impacts. Neck axial forces were recorded, ranging from 2.1 to 3.4 kN. Linear regression analyses were conducted to determine the correlation coefficients that characterised the relationships between dummy responses and impact and sled velocities. Linear regression curves showed that increasing the impact and sled velocities resulted in an increase of the head angular accelerations. The neck axial force was found to positively correlate with the impact and sled velocities in the lateral impacts.

Fatality risk for motorcyclists in fixed object collisions

Motorcyclists contribute significantly to road trauma around the world through the high incidence of serious injuries and fatalities. Around one fourth of motorcyclist fatalities may be attributed to collisions with fixed objects. A greater understanding of factors associated with fatalities occurring from fixed object collisions will enable safer roadway infrastructure design for motorcyclists. In this article, a multiple variable logistic regression model is developed to determine such factors, from a nationally representative weighted sample of around 30,000 single-vehicle fixed object motorcycle collisions which occurred in the United States over the 10-year period between 2000 and 2009. Additionally, a single variable logistic regression model is developed for motorcyclist fatality risk from fixed object collisions as a function of travel speed. This model may be a useful predictive tool for implementing motorcyclist safety strategies.

The Protective Effect of Roadside Barriers for Motorcyclists

Objective: Roadside barriers are often deployed between road users and fixed hazards to protect users from injury. However, the United States and Australian Roadside Design Guides do not consider motorcyclists in the risk-based decision process for the deployment of a barrier, because the severity indices for barriers and fixed hazards were developed for passenger vehicles. The aim of the present article is to quantify the protective effect of barriers with regards to motorcyclist injury and to thereby inform the Roadside Design Guides as to the relative severity of roadside hazards and infrastructure for motorcyclists. Method: A retrospective case series study, using linked police-reported road crash and hospital admission data in New South Wales, Australia, from 2001 to 2009 was performed. Crude and adjusted relative risks of motorcyclist serious injury were determined for various fixed objects compared to barriers, using serious injury rates and multiple variable logistic regression. Calculated relative risks compared with guardrail for motorcyclists were compared with those determined from the United States and Australian Roadside Design Guides for passenger vehicle occupants. Results: The study identified 1364 motorcyclists injured as a result of single-vehicle collisions with roadside barriers, trees, utility poles, and other fixed roadside infrastructure. Trees, posts, and utility poles were shown to provide significantly higher risks of serious injury to motorcyclists compared to barriers. This was also found to be true for serious injuries to particular body regions, such as the head, spine, and torso. The results for motorcyclists were in reasonable agreement with those derived from severity indices in the United States and Australian Roadside Design Guides for passenger vehicle occupants. Conclusions: Roadside barriers provide a significant reduction in the risk of serious injury to motorcyclists compared to various roadside hazards. The provisions in the United States and Australian Roadside Design Guides for passenger vehicle occupants are generally applicable to motorcyclists and support the prior and ongoing use of such guides for designing roadsides that reduce the risk of injury to motorcyclists. However, a more realistic estimation might be derived by increasing the severity indices for barriers by around 25 percent for motorcyclists.

Validation of a dynamic rollover test device

The Jordan Rollover System (JRS) is a device designed, with minimal constraints, to simulate a dynamic trip-over rollover crash. It has been shown to perform with a high degree of repeatability in regards to test protocol inputs and vehicle performance outputs and is the test device of choice for three separate research facilities around the world. The performance of a selection of vehicles, as tested on the JRS at the Center for Injury Research, was compared via logistic regression to their real world injury rate in single-vehicle rollovers using police-reported crash data. Results indicate that vehicles which experienced more roof crush in a JRS test generally experienced higher rates of incapacitating and fatal injury in real world rollover crashes.

The Crash Mechanics of Fatal Motorcycle–Barrier Collisions in Australasia

Motorcyclists contribute significantly to road trauma around the world through the high incidence of serious injuries and fatalities. The role of roadside safety barriers in such trauma is an area of growing concern among motorcyclists, road authorities, and road safety researchers and advocates. This article presents a case series analysis of motorcyclists that were fatally injured following a collision with a roadside barrier during the period 2001 to 2006 in Australia and New Zealand. The crash mechanics of the fatal motorcycle–barrier collisions are detailed, with the aims of providing an understanding of the manner in which these types of crashes occur, informing motorcycle–barrier crash test protocols, and for crash reconstruction purposes. The detailed descriptions of the mechanics of the crashes include barrier and motorcycle types, crash postures, motorcyclist kinematics, precrash speeds, impact trajectory angles, and motorcyclist kinetic energy dissipation on the barrier. Recommendations are made with regards to appropriate motorcycle–barrier crash test protocols.

Motorcyclist Impacts into Roadside Barriers: Is the European Crash Test Standard Comprehensive Enough?

This paper reports on a study that reviewed the European Standard EN 1317-8 for motorists crashing into barriers and the relevance to Australian motorcycle fatalities. The data collection and analysis of 78 Australian motorcyclist-into-barrier fatalities described here were used to justify the review. In Australia each year approximately 15 motorcyclists die from striking a road safety barrier. A retrospective analysis of the fatalities during 2001 to 2006 (n = 78) was carried out. Consistent with European findings, approximately half the motorcyclists were in the upright posture when they struck the barrier, whereas half slid into the barrier. The mean precrash speed was 100.8 km/h, and the mean impact angle was 15.48. The areas of the body that were injured were similar across different barrier types (concrete, wire rope, and W-beam) and crash postures. The thorax area had the highest incidence of injury and maximum injury in fatal motorcycle crashes into barriers; the head area had the second-highest incidence of injury. Moreover, thorax and pelvis injuries had a greater association with sliding crashes than with those in the upright posture. The existing European Standard EN 1317-8 addresses only the sliding mechanism, uses a head injury criterion, and does not specify any thorax injury criterion. It was proposed that a thorax injury criterion and an additional test should be introduced with the rider in the upright position when striking the barrier and then sliding along the top of the barrier.

ICD-based injury severity for land transport trauma

Background Land transport crashes are responsible for a large proportion of injury-related morbidity and subsequent disability. The accurate identification of land transport morbidity is essential to inform and evaluate countermeasures and policy. Aims/Objectives/Purpose To develop and compare ICD-based non-fatal injury severity measures, in order to accurately define injury severity resulting from land transport crashes. Methods All land transport hospital admissions and fatalities from 2001 to 2007 in New South Wales, Australia, were examined. Previously published limitations of the ICD-based International Classification Injury Severity Score (ICISS) were addressed by: including multiple admissions and deaths that occurred outside hospital using data linkage; including comorbidity and age; and accounting for multiple injuries, using multiplicative or worst injury methods. The performance of the different approaches in predicting mortality was assessed with multivariate logistic regression, by comparing the discrimination, calibration and goodness-of-fit. Results/Outcomes There were 109u2005843 land transport hospital admissions during the study period, of which 3471 were fatalities. The inclusion of age and comorbidity improved the prediction of mortality for all ICISS methods. The inclusion of multiple admissions and deaths outside hospital substantially improved the performance of ICISS. ICISS determined from the worst injury had improved discrimination and goodness-of-fit compared with the multiplicative method, for individuals with multiple injuries. The superior ICISS approach demonstrated excellent predictive power (concordance of 0.950). Significance/Contribution to the Field ICISS is a robust predictor of mortality for land transport trauma. Superior performance was achieved with the worst injury method, and including age, comorbidity, multiple admissions and deaths outside hospital.