The road most travelled: the geographic distribution of road traffic injuries in England

Investigation on the driver-victim pairs in pedestrian and bicyclist crashes by latent class clustering and random forest algorithm

Pedestrians and bicyclists from marginalized and underserved populations experienced disproportionate fatalities and injury rates due to traffic crashes in the US. This disparity among road users of different races and the increasing trend of traffic risk for underserved racial groups called for an urgent agenda for transportation policy making and research to ensure equity in roadway safety. Pedestrian and bicyclist crashes involved drivers and pedestrians/bicyclists; the latter were usually victims. Traditional safety studies did not account for the interaction between the two parties and assumed that they were independent from each other. In this study we paired the driver and pedestrian/bicyclist involved in the same crash to understand the socioeconomic and demographic make-up of the two parties involved in crashes and assessed the geographic distribution of these crashes and crash-contributing factors. For this purpose, we applied thelatent class clustering analysis (LCA) to classify different crash types and analyze the patterns of the crashes based on the income and ethnicity of both drivers and victims involved in pedestrian and bicyclist crashes. We then used random forest algorithms and partial dependence plots (PDPs) to model and interpreted the contributing factors of the clusters in both pedestrian and bicyclist models. The clustering results showed a pattern of social segregation in pedestrian and bicyclist crashes that drivers and victims with similar socioeconomic characteristics tend to be involved in one crash. Pedestrian/bicyclist exposure, driver's age, victim's age, year of the car in use, annual average daily traffic (AADT), speed limit, roadbed width, and lane width were the most influential factors contributing to this pattern. Crashes that involved drivers and victims with lower income and non-white ethnicity tended to happen in the location with higher pedestrian/bicyclist exposure, higher speed limit, and wider road. The findings of this research can help to inform the decision-making process for improving safety to ensure equitable and sustainable safety for all road users and communities.

Comparison of motor vehicle-involved e-scooter and bicycle crashes using standardized crash typology

INTRODUCTION

The market share of e-scooters in the United States has proliferated in cities: 86 million trips were made on shared e-scooters in 2019, a more than 100% increase compared to 2018. However, the interaction of e-scooters with other road users and infrastructure remains uncertain.

METHOD

This study scrutinized 52 e-scooter and 79 bicycle police-reported crashes in Nashville, Tennessee, from April 2018 to April 2020 from the Tennessee Integrated Traffic Analysis Network (TITAN) database. We used descriptive analysis and a recent prototype version of the Pedestrian and Bicycle Crash Analysis Tool (PBCAT) to classify crashes based on the locations of the crashes relative to roadway segments or intersections, as well as the maneuver of the motor vehicle and e-scooter/bicycle relative to the motor vehicle.

RESULTS

Two crash typologies can explain the majority of e-scooter crashes, while bicycle crashes are distributed over several crash typologies. Additionally, 1 in 10 e-scooter- and bicycle-motor vehicle crashes leads to the injury or fatality of the e-scooter rider or bicyclist. Furthermore, we noted statistically significant differences in spatial and temporal distribution, demographics, lighting conditions, and crash distance from home for e-scooter and bicycle crashes.

CONCLUSIONS

The police crash report provides a comprehensive picture of e-scooter safety complementing existing literature. We found that e-scooter crash characteristics do not fully overlap with features of bicycle crashes.

PRACTICAL IMPLICATIONS

A generalized engineering, education, and enforcement treatment to reduce and prevent e-scooter and bicycle crashes, injuries, and fatalities might not result in equal outcomes for each mode. More rigorous enforcement could be implemented to deter e-scooters riders under the age of 18 years and e-scooter safety campaigns could target female riders.

Association Between State Medicaid Expansion and Emergency Access to Acute Care Hospitals in the United States

IMPORTANCE

State decisions not to expand Medicaid under the Patient Protection and Affordable Care Act could reduce emergency access to acute care hospitals.

OBJECTIVE

To determine the relationship between state Medicaid expansion and emergency access to acute care hospitals in the United States.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study linked hospital-level data from the Centers for Medicare & Medicaid Services from 2007 to 2017 to US Census data for all 50 US states and the District of Columbia. Geospatial analyses and difference-in-differences regression models were used to compare temporal changes in the size of the population without 30-minute access to acute care hospitals between 32 states that expanded Medicaid with the population without access in 19 that did not, before and after expansion. Analyses focused on the total population and those with low incomes; secondary analyses examined emergency access to safety-net hospitals.

EXPOSURES

State-level Medicaid expansion.

MAIN OUTCOMES AND MEASURES

Population without emergency access to an acute care hospital, defined as living outside a 30-minute drive of any hospital.

RESULTS

States that did not expand Medicaid experienced an increase in the population without access to hospitals overall (without expansion: 6.76% to 6.79% [0.03%]; vs with expansion: 5.65% to 5.35% [-0.30%]; difference-in-differences, 0.33%; 95% CI, 0.33%-0.34%; P < .001) and for low-income persons (without expansion: 7.43% to 7.39% [-0.04%]; vs with expansion: 6.25% to 6.15% [-0.10%]; difference-in-differences, 0.06%; 95% CI, 0.05%-0.07%; P < .001). If access changes in nonexpansion states were the same as expansion states, an estimated 421 000 more persons overall and 48 000 more low-income persons would have retained access. States that did not expand Medicaid experienced an increase in the population without access to safety-net hospitals overall (46.91% to 47.70% [0.79%] vs 33.94% to 33.07% [-0.87%]; difference-in-differences, 1.66%; 95% CI, 1.64%-1.66%; P < .001) and for low-income persons (45.28% to 46.14% [0.86%] vs 33.00% to 32.23% [-0.77%]; difference-in-differences, 1.63%; 95% CI, 1.63%-1.67%; P < .001). If access changes in nonexpansion states were the same as expansion states, an estimated 2 242 000 more persons overall and 364 000 more low-income persons would have retained access.

CONCLUSIONS AND RELEVANCE

States that did not expand Medicaid under the Patient Protection and Affordable Care Act were associated with worse emergency access to acute care hospitals compared with states that expanded Medicaid.

Optimizing access and configuration of trauma centre care in New South Wales

INTRODUCTION

Getting the right patient, to the right place, at the right time is dependent on a multitude of modifiable and non-modifiable factors. One potentially modifiable factor is the number and location of trauma centres (TC). Overabundance of TC dilutes volumes and could be associated with worse outcomes. We describe a methodology that evaluates trauma system reconfiguration without reductions in potential access to care. We used the mature trauma system of New South Wales (NSW) as a model given the perceived overabundance of urban major trauma centres (MTC).

METHODS

We first evaluated potential access to TC care via ground and air transport through the use of geographic information systems (GIS) network analysis. Potential access was defined as the proportion of the population living within 60-min transport time from a potential scene of injury to a TC by ground or rotary-wing aircraft. Sensitivity analyses were carried out in order to account for potential pre-hospital interventions and/or transport delays; travel times of 15-, 30-, 45-, 60-, and 90-min were also analyzed. We then evaluated if the current configuration of the system (number of urban MTS in the Sydney basin) could be optimized without reductions in potential access to care using two GIS methodologies: location-allocation and individual removal of MTC.

RESULTS

86% of the NSW population has potential access to a TC within 60 min ground travel time; potential access improves to 99% with rotary-wing transport. The 1% of the population without potential TC access lives in 48% of the land area (>384,000km2). Utilizing two different methodologies we identified that there was no change in potential access by ground transport after removing 1 or 2 MTC in the Sydney basin at the 30-, 45-, and 60-min transport times. However, 0.02% and 0.5% of the population would not have potential access to MTC care at 15 min after removing one and two MTC respectively.

DISCUSSION

Redistribution of the number of MTC in the Sydney basin could be achieved without a significant impact on potential access to care. Our approach can be utilized as an initial tool to evaluate a trauma system where overabundance of coverage is present.

Nationwide risk factors for hospital readmission for subsequent injury after motor vehicle crashes

OBJECTIVE

Some drivers involved in motor vehicle crashes across the United States may be identified as at risk of subsequent injury by a similar mechanism. The purpose of this study was to perform a national review of the risk factors for hospitalization for a new injury due to a subsequent motor vehicle crash. It was hypothesized that presenting to a different hospital after subsequent injury would result in worse patient outcomes when compared to presentation at the same hospital.

METHODS

The Nationwide Readmissions Database for 2010-2014 was queried for all inpatient hospitalizations with injury related to motor vehicle traffic. The primary patient outcome of interest was subsequent motor vehicle crash-related injury within 1 year. The secondary patient outcomes were different hospital subsequent injury presentation, higher Injury Severity Score (ISS), longer length of stay (LOS), and in-hospital death after subsequent injury. The analysis of secondary patient outcomes was performed only on patients who were reinjured. Univariable analysis was performed for each outcome using all variables during the index admission. Multivariable logistic regression was performed using all significant (P < .05) variables on univariate analysis. Results were weighted for national estimates.

RESULTS

During the study period, 1,008,991 patients were admitted for motor vehicle-related injury; 12,474 patients (1.2%) suffered a subsequent injury within 1 year. From the reinjured patients, 32.9% presented to a different hospital, 48.9% had a higher ISS, and 22.1% had a longer LOS. The in-hospital mortality rate after subsequent injury was 1.1%. Presentation to a different hospital for subsequent injury was associated with a longer LOS (odds ratio [OR] = 1.32; 95% confidence interval [CI], 1.20-1.45; P < .01) and a higher ISS (OR = 1.38; 95% CI, 1.27-1.49; P < .01). Motorcyclists were more likely to suffer subsequent injury (OR = 1.39; 95% CI, 1.32-1.46; P < .01) and motorcycle passengers were more likely to present to a different hospital with a subsequent injury (OR = 2.49; 95% CI, 1.73-3.59; P < .01). Alcohol abuse was associated with subsequent injury (OR = 1.12; 95% CI, 1.07-1.18; P < .01).

CONCLUSIONS

Nearly a third of patients suffering subsequent motor vehicle crash-related injury after an initial motor vehicle crash in the United States present to a different hospital. These patients are more likely to suffer more severe injuries and longer hospitalizations due to their subsequent injury. Future efforts to prevent these injuries must consider the impact of this fragmentation of care and the implications for quality and cost improvements.

Multivariate random parameter Tobit modeling of crashes involving aging drivers, passengers, bicyclists, and pedestrians: Spatiotemporal variations

The increase in 65 years and older population in the United States compels the investigation of the crashes involving all aging (65+) roadway users (drivers, passengers, bicyclists, and pedestrians) in order to ensure their safety. As such, the objective of this research is to provide a spatiotemporal comparative investigation of the crashes involving these aging roadway users in Florida via concurrently using the same set of predictors in order to obtain comparable findings among them. First, a new metric, namely Crash Rate Difference (CRD) approach is developed, which enables one to capture potential spatial and temporal (e.g., weekend and weekday) variations in crash rates of aging user-involved crashes. Second, a multivariate random parameter Tobit model is utilized to determine the factors that drive both the crash occurrence probability and the crash rate of 65+ roadway users, accounting for the unobserved heterogeneity. Findings show that there are statistically significant heterogeneous effects of predictors on the crash rates of different roadway users, which evidences the unobserved heterogeneity across observations. Results also indicate that the presence of facilities such as hospitals, religious facilities, or supermarkets is very influential on crash rates of 65+ roadway users, advocating that roadways around these facilities should be particularly scrutinized by road safety stakeholders. Interestingly, the effect of these facilities on crashes also differs significantly between weekdays and weekends. Moreover, the roadway segments with high crash rates vary temporally depending on whether it is a weekday or a weekend. These findings regarding the spatiotemporal variations clearly indicate the need to develop and design better traffic safety measures and plans addressing these specific roadway segments, which can be tailored to alleviate traffic safety problems for 65+ roadway users.

Factors associated with the occurrence of injuries requiring hospital transfer among older and working-age pedestrians in Kurume, Japan

Background

Pedestrian injuries among older people tend to occur near their residence. However, knowledge regarding whether distance travelled from home to the injury site or road environmental/socioeconomic factors affect injury severity remains limited.

Methods

A cross-sectional study was performed using injury registry data from the Kurume City Fire Department, Japan. Distance travelled from home was determined with geographic information system (GIS) software. Data were analyzed for potential association with injury occurrence and severity, with stratification by age. Signal detection analysis using 10 variables was applied to identify factors associated with the occurrence of severe pedestrian injuries.

Results

Among the 545 adult pedestrian injuries reviewed, the factors associated with the occurrence of severe pedestrian injuries for older people and working-age people were evaluated, focusing on the effect of the network distance travelled from home to injury site. Network distance travelled from home to injury site was not associated with the occurrence of severe pedestrian injuries among older people. By applying signal detection analysis, for older people, higher socioeconomic status, wider road width per lane, and higher aging rate in the residential area were significant factors, and for working-age pedestrians, longer network distance travelled between injury place and their residential area and a higher aging rate in the residential area were significantly associated.

Conclusions

To reduce severe pedestrian injuries among older people, improvement of road infrastructure in areas with wider roads, higher socioeconomic status and higher aging rates is required.

Time trend analyses of child pedestrian morbidity in Japan

OBJECTIVES

Road traffic injuries, particularly pedestrian injuries, are a major health issue among children worldwide. The present study quantitatively analyzed the time trends of child pedestrian injuries in Japan from 1975 to 2013 by age.

STUDY DESIGN

Time trend analysis of nationally aggregated data.

METHODS

We analyzed police data on pedestrian injuries requiring medical treatment among children aged 0-15 years occurring between 1975 and 2013. To quantify the time trends of pedestrian injury morbidity rates and to identify change-points in the trends, joinpoint regression analysis was applied by age group. Children were categorized into the age groups of 0-3, 4-6, 7-9, 10-12, and 13-15 years old.

RESULTS

Preschool children aged 0-6 years old showed continuous declining trends throughout the study period; these declining trends accelerated in the 2000s. School-age children aged 7-15 years old showed minimal changes from the early 1970s to the 1990s; of this age group, children aged 7-12 years old showed slight but significant declining trends in the first half and increasing trends in the latter half of this period. Children aged 7-15 years old showed declining trends in the 2000s. Despite the consistent declining trends among all age groups in the 2000s, the younger age groups showed steeper declines during this period.

CONCLUSIONS

The declining trends in all age groups in the 2000s may reflect the improved traffic environments in Japan although the environmental approaches are not yet sufficiently adopted yielding modest effects. The continuing contrast between preschool and school-age children may reflect different behaviour changes by age such as more restricted outdoor activities among young children.

Interactions of problematic mobile phone use and psychopathological symptoms with unintentional injuries: a school-based sample of Chinese adolescents

Background

Unintentional injuries are a major contributor to morbidity and mortality in adolescents. Mobile phone use in certain circumstances (e.g., driving, cycling, walking) and mental health conditions are risk factors for unintentional injury. However, research on the interactions between problematic mobile phone use (PMPU) and psychopathological symptoms in unintentional injuries is limited. The present study aimed to determine the prevalence of unintentional injuries (road traffic injuries, pedestrian collisions, and falls) and examined interactions of PMPU and psychopathological symptoms with unintentional injuries in a school-based sample of Chinese adolescents.

Methods

A total of 14,221 students (6915 middle school students and 7306 high school students) were randomly selected from 32 schools in four cities in China in 2012. The sample comprised 6712 boys and 7509 girls with a mean age of 15.12 years (standard deviation 1.89 years). PMPU, psychopathological symptoms, and unintentional injuries were measured with validated instruments. Chi-square tests and multivariable logistic regression were used to analyze the rates of unintentional injuries, the relationship with PMPU and psychopathological symptoms, and the interactions of PMPU and psychopathological symptoms with unintentional injuries.

Results

The prevalence of road traffic injuries, pedestrian collisions, and falls were 4.9, 16.2, and 10.1 %, respectively. The rates of unintentional injuries were higher among students with PMPU and psychopathological symptoms. Interaction analysis indicated that psychopathological symptoms were associated with a greater increase in the likelihood of unintentional injuries for adolescents with PMPU than for those without PMPU.

Conclusions

The findings indicate that unintentional injuries in adolescents are an important public health issue in China that merit further research. Intervention programs must consider the adolescents’ behavioral and psychological health.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-2776-8) contains supplementary material, which is available to authorized users.

Hospital-based emergency department visits in children with motor vehicle traffic accidents: estimates from the nationwide emergency department sample

BACKGROUND

The purpose of this study is to provide nationally representative estimates of children visiting hospital-based emergency departments (ED) for motor vechicle traffic accidents (MVTA) in the United States during the year of 2008.

METHODS

Nationwide Emergency Department Sample for 2008 was used. All pediatric (age ≤18 years) ED visits with external cause for injury ICD-9-diagnostic codes for MVTA were selected. Outcomes examined included discharge status following ED visit and presence of concomitant injuries. Descriptive statistics was used to summarize the estimates.

RESULTS

Totally 604 027 hospital-based ED visits occurred in the United States among children (age ≤18 years) due to MVTA. Following an ED visit, 91% were discharged routinely, while 6% were admitted as inpatients into the same hospital. A total of 928 children died in the ED. A total of 34 004 ED visits required inpatient admission into the same hospital and 768 patients died during hospitalization. Mean charge per ED visit was $1887 and total ED charges across the United States were close to $970 million. Among those admitted into the same hospital following ED visit (n=34 004), the mean hospitalization charge was $53 726 and total hospitalization charge across the entire United States were $1.8 billion.

CONCLUSIONS

Study findings illustrate the burden associated with pediatric ED visits due to MVTA. Close to $970 million of hospital charges were incurred by children who made an ED visit due to a MVTA during 2008 and about $1.8 billion was incurred among those hospitalized following an ED visit.

Prediction of vehicle crashes by drivers' characteristics and past traffic violations in Korea using a zero-inflated negative binomial model

AIMS

Traffic safety is a significant public health challenge, and vehicle crashes account for the majority of injuries. This study aims to identify whether drivers' characteristics and past traffic violations may predict vehicle crashes in Korea.

METHODS

A total of 500,000 drivers were randomly selected from the 11.6 million driver records of the Ministry of Land, Transport and Maritime Affairs in Korea. Records of traffic crashes were obtained from the archives of the Korea Insurance Development Institute. After matching the past violation history for the period 2004-2005 with the number of crashes in year 2006, a total of 488,139 observations were used for the analysis. Zero-inflated negative binomial model was used to determine the incident risk ratio (IRR) of vehicle crashes by past violations of individual drivers. The included covariates were driver's age, gender, district of residence, vehicle choice, and driving experience.

RESULTS

Drivers violating (1) a hit-and-run or drunk driving regulation at least once and (2) a signal, central line, or speed regulation more than once had a higher risk of a vehicle crash with respective IRRs of 1.06 and 1.15. Furthermore, female gender, a younger age, fewer years of driving experience, and middle-sized vehicles were all significantly associated with a higher likelihood of vehicle crashes.

CONCLUSIONS

Drivers' demographic characteristics and past traffic violations could predict vehicle crashes in Korea. Greater resources should be assigned to the provision of traffic safety education programs for the high-risk driver groups.

Is ethnic density associated with risk of child pedestrian injury? A comparison of inter-census changes in ethnic populations and injury rates

OBJECTIVES

Research on inequalities in child pedestrian injury risk has identified some puzzling trends: although, in general, living in more affluent areas protects children from injury, this is not true for those in some minority ethnic groups. This study aimed to identify whether 'group density' effects are associated with injury risk, and whether taking these into account alters the relationship between area deprivation and injury risk. 'Group density' effects exist when ethnic minorities living in an area with a higher proportion of people from a similar ethnic group enjoy better health than those who live in areas with a lower proportion, even though areas with dense minority ethnic populations can be relatively more materially disadvantaged.

DESIGN

This study utilised variation in minority ethnic densities in London between two census periods to identify any associations between group density and injury risk. Using police data on road traffic injury and population census data from 2001 to 2011, the numbers of 'White,' 'Asian' and 'Black' child pedestrian injuries in an area were modelled as a function of the percentage of the population in that area that are 'White,' 'Asian' and 'Black,' controlling for socio-economic disadvantage and characteristics of the road environment.

RESULTS

There was strong evidence (p < 0.001) of a negative association between 'Black' population density and 'Black' child pedestrian injury risk [incidence (of injury) rate ratios (IRR) 0.575, 95% CI 0.515-0.642]. There was weak evidence (p = 0.083) of a negative association between 'Asian' density and 'Asian' child pedestrian injury risk (IRR 0.901, 95% CI 0.801-1.014) and no evidence (p = 0.412) of an association between 'White' density and 'White' child pedestrian injury risk (IRR 1.075, 95% CI 0.904-1.279). When group density effects are taken into account, area deprivation is associated with injury risk of all ethnic groups.

CONCLUSIONS

Group density appears to protect 'Black' children living in London against pedestrian injury risk. These findings suggest that future research should focus on structural properties of societies to explain the relationships between minority ethnicity and risk.

Residence place as a risk factor in different types of fatal car accidents

The association between place of residence, population density, relief and type of event (collision or non-collision of the vehicle) has not been evaluated in developing countries. The main objective of this study is to determine the differential factors associated with the occurrence of deaths of collision and non-collision automobile users in Patagonia, Argentina. A multiple logistic regression analysis was performed using as the dependent variable death by car accident (collision or non-collision of the vehicle) and sex, age, place of residence of the victim, relief and population density as the independent variables. Collision fatalities were related to areas of high population density, while non-collision fatalities were related to areas of low population density, mountainous landscape and place of residence of the victims outside the Patagonian region. The results obtained in this study indicate the need to develop differential primary prevention policies by place of residence of car occupants, focusing on Patagonia non-resident drivers and by emphasising non-collision accidents.