Identification of differential risk hotspots for collision and vehicle type in a directed linear network.

Traffic accidents can take place in very different ways and involve a substantially distinct number and types of vehicles. Thus, it is of interest to know which parts of a road structure present an overrepresentation of a specific type of traffic accident, specially for some typologies of collisions and vehicles that tend to trigger more severe consequences for the users being involved. In this study, a spatial approach is followed to estimate the risk that different types of collisions and vehicles present in the central area of Valencia (Spain), considering the accidents observed in this city during the period 2014-2017. A directed spatial linear network representing the non-pedestrian road structure of the area of interest was employed to guarantee an accurate analysis of the point pattern. A kernel density estimation technique was used to approximate the probability of risk along the network for each collision and vehicle type. A procedure based on these estimates and the sample size locally available within the network was designed and tested to determine a set of differential risk hotspots for each typology of accident considered. A Monte Carlo based simulation process was then defined to assess the statistical significance of each of the differential risk hotspots found, allowing the elaboration of rankings of importance and the possible rejection of the least significant ones.

Hit by a Train: Injury Burden and Clinical Outcomes.

BACKGROUND: Few data exist regarding the train vs. pedestrian (TVP) injury burden and outcomes. OBJECTIVE: This study aimed to examine the epidemiology and outcomes associated with TVP injuries. METHODS: This is a retrospective National Trauma Databank study (January 2007 to July 2012) including trauma patients sustaining TVP injury. Demographics, injury data, interventions, and outcomes were abstracted. Patients injured by a train were compared to patients who sustained an automobile vs. pedestrian (AVP) injury. RESULTS: Of the 152,631 patients struck by ground transportation during the study time frame, 1863 (1.2%) were TVP. Median TVP age was 38 years (interquartile range [IQR] 24-50 years), 81.6% were male, median Injury Severity Score (ISS) was 13 (IQR 6-24). TVP patients were more severely injured (ISS 13 vs. 9; p < 0.001) and required more proximal amputations (13.4% vs. 0.2%; p < 0.001) and cavitary operations (18.2% vs. 2.8%; p < 0.001). TVP patients had higher rates of intensive care unit admission, mechanical ventilation and transfusion, longer length of stay, and higher in-hospital mortality. On multivariable logistical regression, TVP was an independent predictor for higher injury burden, ISS ≥25 (adjusted odds ratio [AOR] 1.650), immediate operative need (AOR 7.535), and complications (AOR 1.317). CONCLUSIONS: TVP is associated with a significant injury burden. These patients have a significantly higher need for immediate operation and more complicated hospital course.

Assessment of the disaster medical response system through an investigation of a 43-vehicle mass collision on Jung-ang expressway.

PURPOSE: It was considered the challenges of the actual response and the potential for improvement, including the activities of the disaster response system, national emergency medical center, and the regional base hospital for the treatment of multiple traffic accident victims. The purpose of this study was to analyze the accident management system through real investigating the multiple collision over 10 vehicles with mass casualty events as a disaster situation. METHODS: This study was retrospective study to analyze the disaster event with multiple collision traffic accident on the expressway in Korea. We visited five medical centers for eight days since the accident occurred and interviewed the injured patients in this accident to examine the health status and medical records. After that, we visited the sixteen car-repair shops in four cities for real investigate about damaged vehicles. According to the arrangement of the accident situation for the accident vehicles through real-world investigation, we reproduced all parts of the accident scene, which were real-world investigated, by the accident situation sketch program. The collected data were summarized by Collision Deformation Classification (CDC) codes, and the medical records of the occupants were assessed using the Injury Severity Score (ISS). RESULTS: The cause of the accident was snow freezing of the road. The information about 72 injured patients on 31 damaged vehicles was collected by phone, visit, and actual accident investigation. Of the 72 patients who were examined, 4 were severely injured and 68 were mildly injured. The accident occurred in the order of Sedan 13 (41.9%), SUV 11 (35.5%), Truck 4 (12.9%), Van 2 (6.5%) and Bus 1 (3.2%). The median value of the age [lower quartile and upper quartile] was 43 [34.5-52] years old and the patients included 25 drivers, 11 passengers, 7 back seat passengers, and 29 bus passengers. CONCLUSION: The primary cause of this mass collision accident was road surface freezing, but the more serious secondary cause was a driver's inability to avoid the accident scene after the first collision. The severely injured occupants were occurred on the roads outside and inside the vehicle. In the event of a disaster, various teams from the police team, firefighting team, DMAT, EMS, road management team are gathered, and communication and command system between each team is important in order to identify and solve the disaster situation. To do this, it is important to develop manuals and prepare for training through repeated simulations.

MOPEDS: The high cost of cheap and poorly legislated transportation for negligent drivers.

INTRODUCTION: This study evaluates the impact of moped crashes in North Carolina, a state with lenient moped legislation by(1) describing the characteristics of moped crashes and (2) estimating the cost burden of moped-related injuries. METHODS: Health and public records of moped crash subjects treated at our hospital were reviewed. Direct costs were billed hospital charges. Indirect costs based on age and outcomes were calculated. RESULTS: Between 2008-2013, 368 subjects were involved in 373 moped crashes. 52% of drivers were intoxicated. 38% of drivers had prior DWIs and 26% had prior revoked licenses. Hospitalized subjects (n = 305) had a combined 2687 hospital days, 695 ICU days and 449 trips to the operating room for treatment of their injuries. Average hospital charges were $70,561 per subject. Total direct and indirect costs of moped injuries were over $26 million and $81 million respectively. Medicaid absorbed most of the direct cost ($13.7 M). Estimated direct cost of moped crashes across the state totaled $133 million. CONCLUSION: Healthcare and financial ramifications of moped collisions are substantial. Laws governing moped drivers and stricter penalties for intoxicated drivers are needed.

Estimating the harms and costs of cannabis-attributable collisions in the Canadian provinces.

INTRODUCTION: In 2012, 10% of Canadians used cannabis and just under half of those who use cannabis were estimated to have driven under the influence of cannabis. Substantial evidence has accumulated to indicate that driving after cannabis use increases collision risk significantly; however, little is known about the extent and costs associated with cannabis-related traffic collisions. This study quantifies the costs of cannabis-related traffic collisions in the Canadian provinces. METHODS: Province and age specific cannabis-attributable fractions (CAFs) were calculated for traffic collisions of varying severity. The CAFs were applied to traffic collision data in order to estimate the total number of persons involved in cannabis-attributable fatal, injury and property damage only collisions. Social cost values, based on willingness-to-pay and direct costs, were applied to estimate the costs associated with cannabis-related traffic collisions. The 95% confidence intervals were calculated using Monte Carlo methodology. RESULTS: Cannabis-attributable traffic collisions were estimated to have caused 75 deaths (95% CI: 0-213), 4407 injuries (95% CI: 20-11,549) and 7794 people (95% CI: 3107-13,086) were involved in property damage only collisions in Canada in 2012, totalling $1,094,972,062 (95% CI: 37,069,392-2,934,108,175) with costs being highest among younger people. DISCUSSION: The cannabis-attributable driving harms and costs are substantial. The harm and cost of cannabis-related collisions is an important factor to consider as Canada looks to legalize and regulate the sale of cannabis. This analysis provides evidence to help inform Canadian policy to reduce the human and economic costs of drug-impaired driving.

Methods to rank traffic rule violations resulting in crashes for allocation of funds.

Education, enforcement and engineering countermeasures are implemented to make road users comply with the traffic rules. Not all the traffic rule violations can be addressed nor countermeasures be implemented at all unsafe locations, at once, due to limited funds. Therefore, this study aims at ranking the traffic rule violations resulting in crashes based on individual ranks, such as 1) frequency (expressed as a function of the number of drivers violating a traffic rule and involved in crashes), 2) crash severity, 3) total crash cost, and, 4) cost severity index, to assist transportation system managers in prioritizing the allocation of funds and improving safety on roads. Crash data gathered for the state of North Carolina was processed and used in this study. Variations in the ranks of traffic rule violations were observed when individual ranking methods are used. As an example, exceeding authorized speed limit and driving under the influence of alcohol are ranked 1st and 2nd based on crash severity while failure to reduce speed and failure to yield the right-of-way are ranked 1st and 2nd based on frequency. To minimize the variations and capture the merits of individual ranking methods, four different composite ranks were computed by combining selected individual ranks. The computed averages and standard deviations of absolute rank differences between composite ranks is lower than those obtained from individual ranks. The weights to combine the selected individual ranks have a marginal effect on the computed averages and standard deviations of absolute rank differences. Combining frequency and crash severity or cost severity index, using equal weights, is recommended for prioritization and allocation of funds.

Assessment of trauma patients.

Trauma is a major contributor to global mortality and morbidity with a notable difference between low income countries (LIC) and high to moderate income countries (HMIC). The modality of trauma differs globally; however, the most notable cause is pedestrian vs. vehicle and road traffic collision respectively. It is imperative that patients who have sustained a traumatic injury are managed in an appropriate and timely manner. Part 1 of the article will address the aetiology and demographic distribution of trauma globally and part 2 of the article will provide information about structured assessment and management of trauma patients.

Investigation of a supplementary tool to assist in the prioritization of emphasis areas in North American strategic highway safety plans.

An important potential benefit of a jurisdiction developing an upper-level traffic safety policy statement, such as a strategic highway safety plan (SHSP) or a traffic safety action plan, is the creation of a manageable number of focus areas, known as emphasis areas. The responsible agencies in the jurisdiction can then direct their finite resources in a systematic and strategic way designed to maximize the effort to reduce the number and severity of roadway collisions. In the United States, the federal government through AASHTO has suggested 22 potential emphasis areas. In Canada, CCMTA's 10 potential emphasis areas have been listed for consideration. This study reviewed the SHSP and traffic safety action plan of 53 jurisdictions in North America, and conducted descriptive data analyses to clarify the issues that currently affect the selection and prioritization process of jurisdiction-specific emphasis areas. We found that the current process relies heavily on high-level collision data analysis and communication among the SHSP stakeholders, but may not be the most efficient and effective way of selecting and prioritizing the emphasis areas and allocating safety improvement resources. This study then formulated a formal collision diagnosis test, known as the beta-binomial test, to clarify and illuminate the selection and the prioritization of jurisdiction-specific emphasis areas. We developed numerical examples to demonstrate how engineers can apply the proposed diagnosis test to improve the selection and prioritization of individual jurisdictions' emphasis areas.

EMS Provider assessment of vehicle damage compared with assessment by a professional crash reconstructionist.

OBJECTIVE: To determine the accuracy of emergency medical services (EMS) provider assessments of motor vehicle damage when compared with measurements made by a professional crash reconstructionist. METHODS: EMS providers caring for adult patients injured during a motor vehicle crash and transported to the regional trauma center in a midsized community were interviewed upon emergency department arrival. The interview collected provider estimates of crash mechanism of injury. For crashes that met a preset severity threshold, the vehicle's owner was asked to consent to having a crash reconstructionist assess the vehicle. The assessment included measuring intrusion and external automobile deformity. Vehicle damage was used to calculate change in velocity. Paired t-test, correlation, and kappa were used to compare EMS estimates and investigator-derived values. RESULTS: Ninety-one vehicles were enrolled; of these, 58 were inspected and 33 were excluded because the vehicle was not accessible. Six vehicles had multiple patients. Therefore, a total of 68 EMS estimates were compared with the inspection findings. Patients were 46% male, 28% were admitted to hospital, and 1% died. The mean EMS-estimated deformity was 18 inches and the mean measured deformity was 14 inches. The mean EMS-estimated intrusion was 5 inches and the mean measured intrusion was 4 inches. The EMS providers and the reconstructionist had 68% agreement for determination of external automobile deformity (kappa 0.26) and 88% agreement for determination of intrusion (kappa 0.27) when the 1999 American College of Surgeons Field Triage Decision Scheme criteria were applied. The mean (± standard deviation) EMS-estimated speed prior to the crash was 48 ± 13 mph and the mean reconstructionist-estimated change in velocity was 18 ± 12 mph (correlation -0.45). The EMS providers determined that 19 vehicles had rolled over, whereas the investigator identified 18 (kappa 0.96). In 55 cases, EMS and the investigator agreed on seat belt use; for the remaining 13 cases, there was disagreement (five) or the investigator was unable to make a determination (eight) (kappa 0.40). CONCLUSIONS: This study found that EMS providers are good at estimating rollover. Vehicle intrusion, deformity, and seat belt use appear to be more difficult for EMS to estimate, with only fair agreement with the crash reconstructionist. As expected, the EMS provider -estimated speed prior to the crash does not appear to be a reasonable proxy for change in velocity.

Injury outcomes and costs for cross-median and median barrier crashes.

INTRODUCTION: The objective of this research was to quantify the injury outcomes and develop reliable and comprehensive injury costs for cross-median crashes (CMC) and median barrier crashes (MBC). METHOD: A three-step methodology was developed to quantify the crash costs for each crash severity and type. All CMC and MBC between 2001 and 2007 in Wisconsin were identified and used in this analysis. The Wisconsin CODES database provided comprehensive injury costs based on the injury types and severities suffered by participants in study crashes. RESULTS: As expected, multi-vehicle CMC result in more total injuries and more severe injuries than single-vehicle CMC. Injury costs for the same injury level on KABCO scale are different for different crash types. Injury costs for concrete MBC are 33% to 50% less than those of multi-vehicle CMC, while the injury costs of concrete MBC for lower severities (B and C) are similar to those of single-vehicle CMC for the same severities; but for incapacitating injuries the costs are 30% less. As expected, concrete MBC result in lower severities than CMC. The costs, by crash severity, vary significantly between different crash types. Concrete median barrier injury crashes are roughly 20% of multi-vehicle CMC costs and 50% of single-vehicle CMC costs. CONCLUSIONS: Results indicate that using one set of crash costs for all crash types biases any evaluation. Therefore, it is recommended that crash-type-specific costs be used in applications such as development of median barrier warrant where specific types of crashes are considered (CMC and MBC). IMPACT ON INDUSTRY: Using crash specific costs can lead to a more realistic benefit-cost analysis and enable better decision-making.

[An optimised assessment of "severely injured patients" for the documentation of road traffic accident black spots]. / Eine optimierte Bewertung "Schwerverletzter" zur Dokumentation von Unfallschwerpunkten im Straßenverkehr.

INTRODUCTION: The success of traffic safety improvement strategies is based on documentation. Analysis and remedy of accident black spots in addition to improvements in automobile production involve the work of traffic engineers, politicians, traffic regulations, police, and medical care. To create priorities, the traffic statistics differentiate accidents in a 3-class system in relation to severe accidents: slightly injured, severely injured and fatally injured (death). This study assesses the validity of the existing classification of "severely injured" compared with the actual injury severity. MATERIAL AND METHOD: We analysed accidents resulting in 182 "severely injured" people in one year in a city model. A synchronisation of anonymous police documentation with the medical notes of admitted casualties which were validated by established trauma scores and medical classification was undertaken. A correlation analysis of length of stay should give indications of the actual injury severity. RESULTS: The study group showed a ubiquitous range of age, sex and injuries despite a relatively low case number. The range of MAIS, ISS and NACA index scores shows the inhomogeneity of the people classified as "severely injured". 70 % of the study group revealed ISS < 16 which means that they are not polytraumatised patients. The correlation analysis according to Spearman certifies the validity of these scores (r MAIS/NACA = 0.645 and r ISS/NACA = 0.592). The further differentiation on the basis of MAIS, ISS and NACA showed that 51 % of the study group should be classified as slightly injured and 83 % of these were discharged in less than 5 days. CONCLUSION: This study shows that the traffic safety classification of "severely injured" people is not sufficient and most severely injured people are not even approximately recorded. We propose that a new continuous link system between police and medical data will be inevitable for future improvements in traffic safety. The use of established trauma scores and a differentiated look at lengths of stay could be an option.

An empirical assessment of fixed and random parameter logit models using crash- and non-crash-specific injury data.

Traditional crash-severity modeling uses detailed data gathered after a crash has occurred (number of vehicles involved, age of occupants, weather conditions at the time of the crash, types of vehicles involved, crash type, occupant restraint use, airbag deployment, etc.) to predict the level of occupant injury. However, for prediction purposes, the use of such detailed data makes assessing the impact of alternate safety countermeasures exceedingly difficult due to the large number of variables that need to be known. Using 5-year data from interstate highways in Indiana, this study explores fixed and random parameter statistical models using detailed crash-specific data and data that include the injury outcome of the crash but not other detailed crash-specific data (only more general data are used such as roadway geometrics, pavement condition and general weather and traffic characteristics). The analysis shows that, while models that do not use detailed crash-specific data do not perform as well as those that do, random parameter models using less detailed data still can provide a reasonable level of accuracy.

A joint-probability approach to crash prediction models.

Many road safety researchers have used crash prediction models, such as Poisson and negative binomial regression models, to investigate the associations between crash occurrence and explanatory factors. Typically, they have attempted to separately model the crash frequencies of different severity levels. However, this method may suffer from serious correlations between the model estimates among different levels of crash severity. Despite efforts to improve the statistical fit of crash prediction models by modifying the data structure and model estimation method, little work has addressed the appropriate interpretation of the effects of explanatory factors on crash occurrence among different levels of crash severity. In this paper, a joint probability model is developed to integrate the predictions of both crash occurrence and crash severity into a single framework. For instance, the Markov chain Monte Carlo (MCMC) approach full Bayesian method is applied to estimate the effects of explanatory factors. As an illustration of the appropriateness of the proposed joint probability model, a case study is conducted on crash risk at signalized intersections in Hong Kong. The results of the case study indicate that the proposed model demonstrates a good statistical fit and provides an appropriate analysis of the influences of explanatory factors.

Can patients with low energy whiplash associated disorder develop low back pain?

800 consecutive claimant generated medicolegal reports were analysed for symptomatology of whiplash associated disorder (WAD) including the presence of mid and low back pain. We aimed to establish whether the two were linked and if so if there were correlations between accident vector and severity. We also aimed to establish if a low back injury could result from a vehicular accident in the absence of a neck injury. In addition we examined if occupant bracing and occupant neutral position at the time of the accident affected symptom patterns. We found that a claimed back injury following WAD was independent of both accident severity and accident vectors, approximately 40% claiming injury in low, medium and high violence groups and with rear, frontal and side impact. We established that it was unusual to have a back injury in the absence of a neck injury (18 out of 325, 5.5%) without a past medical history of back pain (72.2% of this group having previous back pain). Occupant bracing was not protective. We also showed that occupant neutral position was not protective against a back injury. We were surprised that patients with next to no car damage had the same incidence of back pain as those involved in more violent crashes when biomechanically unlikely. The complex biopsychosocial response and the relationship to constitutional factors are discussed. The literature concerning forces across the lumbar spine and possibilities of injury is reviewed.

The relationship between regional economic conditions and the severity of traffic crashes.

OBJECTIVES: To evaluate the relationship between regional economic conditions and the severity of injury suffered by victims of traffic crashes. This analysis augments the research on the relationship between economic conditions and traffic safety by focusing on injury severity per victim, which isolates the protective effect to individuals from other traffic safety effects such as crashes per mile and aggregate exposure to crashes. METHODS: A crash-specific data set from the State of Ohio is used together with county-level economic and demographic data to generate estimates that measure the impact of county-level per capita income and unemployment rate on the severity of injury suffered by each individual who is involved in a crash. The estimates are derived from an ordered probit model that controls for other factors that influence injury severity independently of economic conditions. RESULTS: The resulting estimates indicate that on average, individuals involved in crashes that occur in relatively prosperous counties suffer less severe injuries than those in less prosperous counties, holding other influential factors constant. Regional per capita income has a proportionally greater impact on injury severity than does regional unemployment rate. CONCLUSIONS: The estimates indicate that regional economic conditions have a statistically significant beneficial impact on traffic safety by improving the level of injury suffered by crash victims. Therefore, state and federal public policy makers should consider this factor when allocating traffic safety-related resources among geographical regions.

Building national estimates of the burden of road traffic injuries in developing countries from all available data sources: Iran.

OBJECTIVE: To use a range of existing information sources to develop a national snapshot of the burden of road traffic injuries in one developing country-Iran. METHODS: The distribution of deaths was estimated by using data from the national death registration system, hospital admissions and outpatient visits from a time-limited hospital registry in 12 of 30 provinces, and injuries that received no institutional care using the 2000 demographic and health survey. Results were extrapolated to national annual incidence of health burden differentiated by age, sex, external cause, nature of injuries and institutional care. RESULTS: In 2005, 30,721 Iranians died annually in road traffic crashes and over one million were injured. The death rate (44 per 100,000) is the highest of any country in the world for which reliable estimates are available. Road traffic injuries are the third leading cause of death in Iran. While young adults are at high risk in non-fatal crashes, the elderly have the highest total death rates, largely due to pedestrian crashes. While car occupants lead the death count, motorized two-wheeler riders dominate hospital admissions, outpatient visits and health burden. CONCLUSIONS: Reliable estimates of the burden of road traffic injuries are an essential input for rational priority setting. Most low income countries are unlikely to have national injury surveillance systems for several decades. Thus national estimates of the burden of injuries should be built by collating information from all existing information sources by appropriately correcting for source specific shortcomings.

Short-term physical limitations in children following motor vehicle crashes.

This study describes frequency of injury and short-term physical limitation among child occupants or=1 physical limitations. Limitations increased with age, from 0.7% for childrenor=2 injuries, the proportion with physical limitations ranged from 58% to 91% depending on injury diagnosis. Among children with whiplash, 47% resulted in physical limitations. Suboptimally restrained children were nearly twice as likely to have a limitation compared to optimally restrained children. After adjusting for driver characteristics and vehicle type, child's age, restraint use, and type of initial impact were independently associated with the presence of physical limitations. Our results show the importance of assessing children for physical limitations following motor vehicle crashes. We also observed that children with whiplash were at risk for physical limitations.

Worldsid assessment of far side impact countermeasures.

Far side impact trauma has been demonstrated as a significant portion of the total trauma in side impacts. The objective of the study was to assess the potential usefulness of countermeasures and assess the trade-offs associated with generic countermeasure design. Because the WorldSID dummy has demonstrated promise as a potential far side impact dummy, it was chosen to assess countermeasures in this mode. A unique far side impact buck was designed for a sled test system that included, as a standard configuration, a center console and outboard three-point belt system. This configuration assumed a left side driver with a right side impact. The buck allowed for additional options of generic restraints including shoulder or thorax plates or an inboard shoulder belt. The entire buck could be mounted on the sled in either a 90-degree (3-o'clock PDOF) or a 60-degree (2-o'clock PDOF) orientation. A total of 19 WorldSID tests were completed. The inboard shoulder belt configuration produced high shear forces in the lower neck (2430 N) when the belt position was placed over the mid portion of the neck. Shear forces were reduced and of opposite sign when the inboard belt position was horizontal and over the shoulder; forces were similar to the standard outboard belt configuration (830 - 1100 N). A shoulder or thorax restraint was effective in limiting the head excursion, but each caused significant displacement at the corresponding region on the dummy. A shoulder restraint resulted in shoulder displacements of 30 - 43 mm. A thorax restraint caused thorax deflections of 39 - 64 mm. Inboard restraints for far side impacts can be effective in reducing head excursion but the specific design and placement of these restraints determine their overall injury mitigating characteristics.

San Francisco pedestrian injury surveillance: mapping, under-reporting, and injury severity in police and hospital records.

GOALS: Police reports of severely injured pedestrians help identify hazardous traffic areas in San Francisco, but they under-report non-fatal collisions. We set out to: identify injured pedestrians who were missing from police collision reports, see what biases exist in injury reporting and assess the utility of broad categories of police severe injury (including fatal) for mapping and analysis. METHODS: We linked data on injured pedestrians from police collision reports listed in the Statewide Integrated Traffic Reporting System (SWITRS, n = 1991) with records of pedestrians treated at San Francisco General Hospital (SFGH, n = 1323) for 2000 and 2001. Data were analyzed using bivariate statistics, logistic regression and mapping. RESULTS: : We found that police collision reports underestimated the number of injured pedestrians by 21% (531/2442). Pedestrians treated at SFGH who were African-American were less likely then whites (odds ratio = 0.55, p-value < or= 0.01), and females were more likely than males (odds ratio = 1.5, p-value < or = 0.01) to have a police collision report. Over 70% of pedestrians deemed by the police to have a severe injury received treatment at SFGH, regardless of the collision's distance from SFGH. The sensitivity of a police-designated severe injury (including fatal) was 69% and the specificity was 89% when compared with a known SFGH assessment. But, sensitivity declined when we included pedestrians without a SFGH record. CONCLUSION: Though collision reports have demonstrated limitations, broad categories of police severity may be sensitive enough to map locations where numerous severe injuries occur, for timely countermeasure selection.