Injury Metrics for Assessing the Risk of Acute Subdural Hematoma in Traumatic Events

Worldwide, the ocurrence of acute subdural hematomas (ASDHs) in road traffic crashes is a major public health problem. ASDHs are usually produced by loss of structural integrity of one of the cerebral bridging veins (CBVs) linking the parasagittal sinus to the brain. Therefore, to assess the risk of ASDH it is important to know the mechanical conditions to which the CBVs are subjected during a potentially traumatic event (such as a traffic accident or a fall from height). Recently, new studies on CBVs have been published allowing much more accurate prediction of the likelihood of mechanical failure of CBVs. These new data can be used to propose new damage metrics, which make more accurate predictions about the probability of occurrence of ASDH in road crashes. This would allow a better assessement of the effects of passive safety countermeasures and, consequently, to improve vehicle restraint systems. Currently, some widely used damage metrics are based on partially obsolete data and measurements of the mechanical behavior of CBVs that have not been confirmed by subsequent studies. This paper proposes a revision of some existing metrics and constructs a new metric based on more accurate recent data on the mechanical failure of human CBVs.

Causation of Metro Operation Accidents in China: Calculation of Network Node Importance Based on DEMATEL and ISM

Continuous metro-operation accidents lead to serious economic loss and a negative social impact. The accident causation analysis is of great significance for accident prevention and metro operation safety promotion. Network node importance (NNI) evaluation has been widely used as a tool for ranking the nodes in complex networks; however, traditional indicators such as degree centrality (DC) are insufficient for examining accident networks. This study proposed an improved method by integrating decision making trail and evaluation laboratory (DEMATEL) and interpretive structural modeling (ISM) into traditional NNI evaluation, where the key nodes are determined by both the nature of the accident network topology and the contribution of the nodes to accident development. Drawing on this method, 32 accident causal factors were identified and prioritized on the ground of 248 accident cases. It was found that 14 important factors related to staff (e.g., “driver noncompliance”), environment (e.g., “extrinsic nature disturbance”), passenger (e.g., “passenger sudden illness”), and machine (e.g., “track failures”) should be given priority in safety management due to their significant tendency of causing metro accidents. Theoretical and managerial implications were discussed to provide useful insights into the understanding of the causation of metro accidents and form a basis for metro managers to develop targeted safety countermeasures related to metro operation. The proposed hybrid method is proven effective in investigating accident networks involving sequential and casual relationships and revealing factors with high possibility to increase accidents.

Overview of Intelligent Transportation System Safety Countermeasures for Wrong-Way Driving

Wrong-way driving (WWD) crashes are rare but tend to cause severe injuries and fatalities. When they occur, WWD crashes are mostly head-on and tend to be more severe than any other crash type. Currently, most efforts to mitigate WWD crashes focus on the application of intelligent transportation systems (ITS) technologies. Since the mid-1960s, many agencies have proposed and tested a variety of countermeasures ranging from the conventional, including improvements in signage and pavement markings, to the more advanced, based mainly on ITS. The application of ITS in detecting and deterring WWD crashes involves a combination of several components, such as detection, warning, and action. The main objective of this paper is to provide a comprehensive overview of ITS technologies implemented by different transportation agencies in the mitigation and prevention of WWD crashes. This study proves the importance of ITS technologies that have seen widespread application in recent years. Moreover, according to the evaluation studies of different ITS-related countermeasures, it shows that the countermeasures deployed have been effective in detecting wrong-way drivers and reducing the rate of wrong-way incidents. The results will provide insights for policymakers, engineers, and researchers into the application of ITS for reducing the severity and frequency of WWD crashes and other incidents on highway facilities.

Exploring the Need to Model Two- and Multiple-Vehicle Crashes Separately

Single-vehicle crashes have been shown to differ from two-plus vehicle crashes. Several studies have discussed the issues with modeling single-vehicle and two-plus vehicle crashes together. However, none of the empirical studies have attempted to study two-vehicle (2V) and multiple-vehicle (MV), that is, three-plus crash groups, to understand their correlation and influencing factors. This study first investigated whether there is a need to develop separate safety performance functions for 2V and MV crashes, in addition to single-vehicle crashes. Then, the correlation and influencing factors of 2V and MV were evaluated. Three regression models—a correlated bivariate negative binomial regression (BNR) model, an uncorrelated bivariate negative binomial regression (NR) model, and a univariate negative binomial regression (UNR) model, were developed and compared. The analysis was based on the 2011–2015 crashes that occurred on I-4 in Florida. Findings indicated that the BNR model significantly outperformed the NR and the UNR models. The model results suggest that disaggregating 2V and MV crashes while allowing correlation between the groups for the latent effects in the model best describes the data. Traffic volume, posted speed limit, and median type were found significant in contributing to the occurrence of both 2V and MV crashes. Additional contributing factors for 2V crashes included the presence of interchange influence area, and for MV crashes, the presence of a vertical curve and the presence of a horizontal curve. Study findings could assist transportation officials in implementing specific safety countermeasures for road segments identified as hotspots for 2V and MV crashes.

Spatial distribution and the facility evaluation of the service and rest areas in the toll motorway network of the European Union

Among safety countermeasures for roads, service and rest areas play a vital role, providing a place to stop or rest during a journey and offering services such as petrol stations. Due to their importance, they must be logically distributed along routes at convenient locations with respect to travel itineraries and must be conveniently equipped. These needs become even more apparent on motorways that charge a toll to use the road, because drivers tend avoid leaving the motorway until they have reached their planned destination or departure point. The objective of this paper is to explore the spatial distribution of the service and rest areas on the toll motorways (or freeways) in the European Union (EU) and their facilities. Additionally, the distance and facility specifications established by the regulations of each country were compared. The EU was selected for this evaluation because of the virtual inexistency of borders and the substantial international traffic volumes that result from this relatively free flow of traffic between countries. Countries with a toll road network over 100 km were included: Italy, Portugal, France, Spain, Poland, Greece, and the Slovak Republic. Analysis of average and maximum distances between areas and the facilities provided showed a great variability due to different distribution policies. Few regulations exist that establish maximum distances between areas. Standardization of the spatial distribution of these facilities, on both free and tolled roadways, in the EU would benefit drivers, especially on long journeys, creating a consistent and predictable network of areas and services.

Roadway Lighting’s Effect on Pedestrian Safety at Intersection and Midblock Crosswalks

This study evaluates the visual performance of four intersection lighting designs and five midblock crosswalk lighting designs along with two pedestrian safety countermeasures (rectangular rapid flashing beacons and flashing signs) at three light levels. The study involved a pedestrian detection task, which was completed at night on a realistic roadway intersection and a midblock crosswalk. The results from the study showed that driver nighttime visual performance at intersection and midblock crosswalks was influenced by the lighting design and light level. Intersections should be illuminated to an average horizontal illuminance of 14 lux (1.3 fc). This light level ensures optimal visibility of pedestrians regardless of the lighting design (or luminaire layout) of the intersection. The average horizontal illuminance of 14 lux (1.3 fc) also increases the visibility of pedestrians when glare from oncoming vehicles is present. The 14 lux (1.3 fc) average horizontal illuminance is valid for all lighting designs evaluated except the lighting design that illuminated the exits of the intersection. When the exits of the intersection are illuminated, an average horizontal illuminance of 24 lux (2.2 fc) is needed to offset the disability glare from opposing vehicles. Midblock crosswalks should be illuminated to an average vertical illuminance of 10 lux (0.9 fc) to ensure optimal pedestrian visibility. Where overhead lighting is available, midblock crosswalk lighting designs that render the pedestrian in positive contrast are recommended. Where overhead lighting is not available, crosswalk illuminators can be used to illuminate midblock crosswalks. At night, pedestrian crossing treatments such as rectangular rapid flashing beacons and flashing signs should not be used for pedestrian visibility at midblock crosswalks. Pedestrians crossing treatments should be used in conjunction with overhead lighting or crosswalk illuminators at the established vertical illuminance to ensure optimal pedestrian visibility at midblock crosswalks.

A Novel Acceleration Signal Processing Procedure for Cycling Safety Assessment

With the growing rate of urban population and transport congestion, it is important for a city to have bike riding as an attractive travel choice but one of its biggest barriers for people is the perceived lack of safety. To improve the safety of urban cycling, identification of high-risk location and routes are major obstacles for safety countermeasures. Risk assessment is performed by crash data analysis, but the lack of data makes that approach less effective when applied to cyclist safety. Furthermore, the availability of data collected with the modern technologies opens the way to different approaches. This research aim is to analyse data needs and capability to identify critical cycling safety events for urban context where bicyclist behaviour can be recorded with different equipment and bicycle used as a probe vehicle to collect data. More specifically, three different sampling frequencies have been investigated to define the minimum one able to detect and recognize hard breaking. In details, a novel signal processing procedure has been proposed to correctly deal with speed and acceleration signals. Besides common signal filtering approaches, wavelet transformation and Dynamic Time Warping (DTW) techniques have been applied to remove more efficiently the instrument noise and align the signals with respect to the reference. The Euclidean distance of the DTW has been introduced as index to get the best filter parameters configuration. Obtained results, both during the calibration and the investigated real scenario, confirm that at least a GPS signal with a sampling frequency of 1Hz is needed to track the rider’s behaviour to detect events. In conclusion, with a very cheap hardware setup is possible to monitor riders’ speed and acceleration.

Cognitive Gap and Correlation of Safety-I and Safety-II: A Case of Maritime Shipping Safety Management

In contrast to the conventional safety management principle, namely, safety-I, which focuses on “what goes wrong”, a new-born safety philosophy (safety-II) inspires people to investigate “how and why things go right”. In the present study, the cognitive difference and correlation between safety-I and safety-II in the maritime shipping industry are explored and investigated. For this purpose, a questionnaire is administered to survey seafarers and maritime experts, and semi-structured interviews are conducted to collect original data associated with safety-I and safety-II. Then, the data from seafarers and maritime experts are further processed by empirical statistical methods and fuzzy analytic hierarchy process (AHP) methodology. The results show that impacting factors associated with individual aspects are usually accepted as dominant with respect to views of safety-I, while organizational factors are more influential for safety-II, which is essential to developing an organizational resilience capacity. Based on the findings and discussions, potential safety countermeasures that integrate safety-I and safety-II are proposed in this article. The present study discusses the new-born safety-II perspective to elucidate the safety issues associated with maritime shipping operations, which can be seen as the main innovation of this work.