Christina M. Rudin-Brown

Systems-based accident analysis in the led outdoor activity domain: application and evaluation of a risk management framework

Safety-compromising accidents occur regularly in the led outdoor activity domain. Formal accident analysis is an accepted means of understanding such events and improving safety. Despite this, there remains no universally accepted framework for collecting and analysing accident data in the led outdoor activity domain. This article presents an application of Rasmussens risk management framework to the analysis of the Lyme Bay sea canoeing incident. This involved the development of an Accimap, the outputs of which were used to evaluate seven predictions made by the framework. The Accimap output was also compared to an analysis using an existing model from the led outdoor activity domain. In conclusion, the Accimap output was found to be more comprehensive and supported all seven of the risk management frameworks predictions, suggesting that it shows promise as a theoretically underpinned approach for analysing, and learning from, accidents in the led outdoor activity domain. Statement of Relevance: Accidents represent a significant problem within the led outdoor activity domain. This article presents an evaluation of a risk management framework that can be used to understand such accidents and to inform the development of accident countermeasures and mitigation strategies for the led outdoor activity domain.

Driver distraction in an unusual environment: Effects of text-messaging in tunnels

Text messaging while driving can be distracting and significantly increases the risk of being involved in a collision. Compared to freeway driving, driving in a tunnel environment introduces factors that may interact with driver attentional resources to exacerbate the effects of distraction on driving safety. With planning and design of the 18km Stockholm Bypass tunnel ongoing, and because of the potentially devastating consequences of crashes in long tunnels, it is critical to assess the effects of driver distraction in a tunnel environment. Twenty-four participants (25-50 years) drove in simulated highway and tunnel road environments while reading and writing text messages using their own mobile phones. As expected, compared to driving alone, text messaging was associated with decrements in driving performance and visual scanning behavior, and increases in subjective workload. Speeds were slower compared to baseline (no text-messaging) driving when participants performed the text-messaging tasks in the tunnel environment compared to the freeway, suggesting that drivers may have attempted to compensate more for the increased text-messaging-related workload when they were in the tunnel. On the other hand, increases in lane deviation associated with the most complex text-messaging task were more pronounced in the tunnel compared to on the freeway. Collectively, results imply that driver distraction in tunnels is associated with generally similar driving decrements as freeway driving; however, the potential consequences of these decrements in tunnels remain significantly more serious. Future research should attempt to elucidate the nature of any differential compensatory behavior in tunnel, compared to freeway, driving. In the meantime, drivers should be advised to refrain from text messaging, especially when driving in tunnels.

The Impact of New Legislation on Child Restraint System (CRS) Misuse and Inappropriate Use in Australia

Objective: The current study aimed to investigate the incidence of child restraint system (CRS) misuse and/or inappropriate use of CRS through an Australian CRS inspection program conducted by CRS fitting specialists between October 2004 and October 2011 and to determine whether CRS misuse and/or inappropriate use of CRS changed following new Australian legislation regarding CRS and motor vehicle restraint use for children aged 7 years and under. Methods: Participants were recruited through an advertisement for free CRS inspections displayed at childcare centers, kindergartens, community centers, hospitals, and child expos. At each inspection, a CRS fitting specialist inspected each child in their CRS while in their vehicle and reported to the owner of the CRS on the installation of the child restraint(s) and/or system(s) and any fitting faults and/or concerns with the fitting and/or use of the child restraint(s) and or system(s). Results: Results are based on the inspection of 2674 CRS. Of all of the CRS inspected, the majority (79%) were reported as having at least one instance of misuse and/or inappropriate use. The most common forms of CRS misuse and/or inappropriate use observed were harness strap errors (twisted, poorly adjusted, and/or incorrectly positioned, 41%), seat belt errors (incorrectly routed, twisted, and/or incorrectly adjusted, 32%), and a missing or incorrect fitting of the gated buckle/locking clip (24%). Significant differences were found across the proportion of CRS misuse and/or inappropriate use across restraint types (infant restraint/forward-facing CRS/convertible [birth to 18 kg] CRS/convertible [8–26 kg] CRS/boosters [booster seat/cushion/booster with harness combination]), χ2(4) = 147.852, P < .001. CRS misuse and/or inappropriate use were most prevalent among convertible CRS (birth to 18 kg; 87%), forward-facing CRS (85%), and convertible CRS (8–26 kg; 81%), compared to infant restraints (73%) and booster seats (booster seats/cushions/boosters with H-harness combination; 65%). There was no significant difference in the proportion of CRS with misuse and/or inappropriate use across the pre- and post-legislation period (80% vs. 77%), χ2(1) = 1.545, P > .5. Conclusions: Based on the findings of the current study, it was concluded that, despite the introduction of new, definitive CRS legislation, CRS misuse and/or inappropriate use remains widespread in Australia. The findings highlight the need for CRS education and legislation that include information on correct CRS use, as well as information on appropriate CRS use, in order to provide specialized protection for child vehicle occupants in the event of a motor vehicle crash.

Police Officer In-vehicle Discomfort: Appointments Carriage Method and Vehicle Seat Features

Musculoskeletal pain is commonly reported by police officers. A potential cause of officer discomfort is a mismatch between vehicle seats and the method used for carrying appointments. Twenty-five police officers rated their discomfort while seated in: (1) a standard police vehicle seat, and (2) a vehicle seat custom-designed for police use. Discomfort was recorded in both seats while wearing police appointments on: (1) a traditional appointments belt, and (2) a load-bearing vest/belt combination (LBV). Sitting in the standard vehicle seat and carrying appointments on a traditional appointments belt were both associated with significantly elevated discomfort. Four vehicle seat features were most implicated as contributing to discomfort: back rest bolster prominence; lumbar region support; seat cushion width; and seat cushion bolster depth. Authorising the carriage of appointments using a LBV is a lower cost solution with potential to reduce officer discomfort. Furthermore, the introduction of custom-designed vehicle seats should be considered.

Computer vision and driver distraction: Developing a behaviour-flagging protocol for naturalistic driving data

Naturalistic driving studies (NDS) allow researchers to discreetly observe everyday, real-world driving to better understand the risk factors that contribute to hazardous situations. In particular, NDS designs provide high ecological validity in the study of driver distraction. With increasing dataset sizes, current best practice of manually reviewing videos to classify the occurrence of driving behaviours, including those that are indicative of distraction, is becoming increasingly impractical. Current statistical solutions underutilise available data and create further epistemic problems. Similarly, technical solutions such as eye-tracking often require dedicated hardware that is not readily accessible or feasible to use. A computer vision solution based on open-source software was developed and tested to improve the accuracy and speed of processing NDS video data for the purpose of quantifying the occurrence of driver distraction. Using classifier cascades, manually-reviewed video data from a previously published NDS was reanalysed and used as a benchmark of current best practice for performance comparison. Two software coding systems were developed - one based on hierarchical clustering (HC), and one based on gender differences (MF). Compared to manual video coding, HC achieved 86 percent concordance, 55 percent reduction in processing time, and classified an additional 69 percent of target behaviour not previously identified through manual review. MF achieved 67 percent concordance, a 75 percent reduction in processing time, and classified an additional 35 percent of target behaviour not identified through manual review. The findings highlight the improvements in processing speed and correctly classifying target behaviours achievable through the use of custom developed computer vision solutions. Suggestions for improved system performance and wider implementation are discussed.

User-Centered Label Design Guidelines for Child Restraint Systems

Child Restraint Systems (CRS; car seats) are designed to prevent injuries in motor vehicle collisions. CRS misuse and installation errors are common and may seriously reduce or nullify safety benefits. Poorly designed labels and instructions contribute to CRS misuse, and CRS manufacturers are not held to an evidence-based label design standard. This paper describes a user-centered design (UCD) and evaluation process for infant/child convertible (rear-facing/forward-facing) CRS installation labels. The labels focused on two primary tasks: installing a CRS into a vehicle and securing a child into the CRS. The label design concepts were based on literature identifying primary areas for CRS misuse, Human Factors and UCD principles, product warning and label design standards, and current Canadian and US motor vehicle safety standards. A follow-up study will evaluate the reduction of CRS installation errors based on the hypothesized enhanced label usability and effectiveness.

Modeling Driving Performance Using In-Vehicle Speech Data From a Naturalistic Driving Study

Objective: We aimed to (a) describe the development and application of an automated approach for processing in-vehicle speech data from a naturalistic driving study (NDS), (b) examine the influence of child passenger presence on driving performance, and (c) model this relationship using in-vehicle speech data. Background: Parent drivers frequently engage in child-related secondary behaviors, but the impact on driving performance is unknown. Applying automated speech-processing techniques to NDS audio data would facilitate the analysis of in-vehicle driver–child interactions and their influence on driving performance. Method: Speech activity detection and speaker diarization algorithms were applied to audio data from a Melbourne-based NDS involving 42 families. Multilevel models were developed to evaluate the effect of speech activity and the presence of child passengers on driving performance. Results: Speech activity was significantly associated with velocity and steering angle variability. Child passenger presence alone was not associated with changes in driving performance. However, speech activity in the presence of two child passengers was associated with the most variability in driving performance. Conclusion: The effects of in-vehicle speech on driving performance in the presence of child passengers appear to be heterogeneous, and multiple factors may need to be considered in evaluating their impact. This goal can potentially be achieved within large-scale NDS through the automated processing of observational data, including speech. Application: Speech-processing algorithms enable new perspectives on driving performance to be gained from existing NDS data, and variables that were once labor-intensive to process can be readily utilized in future research.

A Preliminary Estimation of Motorcyclist Fatal Injury Risk by BAC Level Relative to Car/Van Drivers

Objective: This study sought to quantify the fatal injury risks for motorcyclists associated with the riders’ blood alcohol concentrations (BACs). Method: Using a case-control study design with New Zealand data, fatal injury risk curves for motorcyclists and car drivers were modeled. A total of 142 fatally injured drivers/riders (cases) and 58,000 control drivers/riders were studied. For motorcyclists, there were 13 cases and 194 controls. Results: The rate of increase in fatal injury risk with increasing BAC was not found to be different for motorcyclists compared to car/van drivers. However, because the baseline risk for motorcyclists was already considerably higher than for car/van drivers, even modest amounts of alcohol were associated with very high risks for motorcyclists compared to sober car/van drivers. It was estimated that, relative to their sober risk, motorcycle riders at BAC = 0.03 percent have 3 times the fatality risk (95% confidence interval [CI] = 2.8–3.5) and, at BAC = 0.08, 20 times the fatality risk (95% CI = 15.0–27.3). Conclusions: Interventions focused on reducing the alcohol consumption of motorcycle riders are clearly required when the degree of risk even at low alcohol levels is as disturbingly high as estimated in the current study.

Standardized error severity score (ESS) ratings to quantify risk associated with child restraint system (CRS) and booster seat misuse

ABSTRACT Objective: Although numerous research studies have reported high levels of error and misuse of child restraint systems (CRS) and booster seats in experimental and real-world scenarios, conclusions are limited because they provide little information regarding which installation issues pose the highest risk and thus should be targeted for change. Beneficial to legislating bodies and researchers alike would be a standardized, globally relevant assessment of the potential injury risk associated with more common forms of CRS and booster seat misuse, which could be applied with observed error frequency—for example, in car seat clinics or during prototype user testing—to better identify and characterize the installation issues of greatest risk to safety. Methods: A group of 8 leading world experts in CRS and injury biomechanics, who were members of an international child safety project, estimated the potential injury severity associated with common forms of CRS and booster seat misuse. These injury risk error severity score (ESS) ratings were compiled and compared to scores from previous research that had used a similar procedure but with fewer respondents. To illustrate their application, and as part of a larger study examining CRS and booster seat labeling requirements, the new standardized ESS ratings were applied to objective installation performance data from 26 adult participants who installed a convertible (rear- vs. forward-facing) CRS and booster seat in a vehicle, and a child test dummy in the CRS and booster seat, using labels that only just met minimal regulatory requirements. The outcome measure, the risk priority number (RPN), represented the composite scores of injury risk and observed installation error frequency. Results: Variability within the sample of ESS ratings in the present study was smaller than that generated in previous studies, indicating better agreement among experts on what constituted injury risk. Application of the new standardized ESS ratings to installation performance data revealed several areas of misuse of the CRS/booster seat associated with high potential injury risk. Conclusions: Collectively, findings indicate that standardized ESS ratings are useful for estimating injury risk potential associated with real-world CRS and booster seat installation errors.

Usability Study of the Universal Anchorage System (UAS) for Child Restraint Systems (CRS) in School Buses and Passenger Vehicles

There have been no usability studies assessing the new Child Restraint System (CRS) Universal Anchorage System (UAS) since the systems implementation in Canada in 2002. A Within-Subjects design research study involving forty-eight participants was conducted to evaluate how effectively users installed CRSs within a vehicle and a school bus when using different Lower Anchorage Connector (LAC) and Top Tether designs. The research indicates that users are not familiar with the UAS, and that safe installation of CRSs when using the UAS is not intuitive, resulting in significant installation safety errors. Furthermore, CRS users do not understand the severity of their installation errors, and the impact these errors have on compromising child safety. Industry and Regulators must increase UAS awareness, to inform users of the new UAS design and its components, and how the UAS impacts correct and safe CRS installation.