Traffic Safety Improvement Research Articles

A Comprehensive Survey on Cooperative Intersection Management for Heterogeneous Connected Vehicles

Nowadays, with the advancement of technology, world is trending toward high mobility and dynamics. In this context, intersection management (IM) as one of the most crucial elements of the transportation sector demands high attention. Today, road entities including infrastructures, vulnerable road users (VRUs) such as motorcycles, moped, scooters, pedestrians, bicycles, and other types of vehicles such as trucks, buses, cars, emergency vehicles, and railway vehicles like trains or trams are able to communicate cooperatively using vehicle-to-everything (V2X) communications and provide traffic safety, efficiency, infotainment and ecological improvements. In this paper, we take into account different types of intersections in terms of signalized, semi-autonomous (hybrid) and autonomous intersections and conduct a comprehensive survey on various intersection management methods for heterogeneous connected vehicles (CVs). We consider heterogeneous classes of vehicles such as road and rail vehicles as well as VRUs including bicycles, scooters and motorcycles. All kinds of intersection goals, modeling, coordination architectures, scheduling policies are thoroughly discussed. Signalized and semi-autonomous intersections are assessed with respect to these parameters. We especially focus on autonomous intersection management (AIM) and categorize this section based on four major goals involving safety, efficiency, infotainment and environment. Each intersection goal provides an in-depth investigation on the corresponding literature from the aforementioned perspectives. Moreover, robustness and resiliency of IM are explored from diverse points of view encompassing sensors, information management and sharing, planning universal scheme, heterogeneous collaboration, vehicle classification, quality measurement, external factors, intersection types, localization faults, communication anomalies and channel optimization, synchronization, vehicle dynamics and model mismatch, model uncertainties, recovery, security and privacy.

Autonomous Driving and Connected Mobility Modeling: Smart Dynamic Traffic Monitoring and Enforcement System for Connected and Autonomous Mobility

In recent years, autonomous vehicles (AVs), connected vehicles (CVs) and all relative technology have been in the spotlight, being intensively researched and developed. There is high anticipation on the benefits of automation and the overall reform it will bring to the transport sector, with some optimistic estimates considering it as a reality within the next few years. Evidently, AVs and CVs are attracting considerable attention and are developed very rapidly, cultivating great expectations for traffic safety improvements. While their potential is enormous and undeniable, benefits are not automatically guaranteed as there are parameters that currently appear unforeseen. This paper investigates the ways that monitoring and enforcement of autonomous vehicles can be improved and serious problems such as tailgating and crashes can be mitigated. This paper's result could provide useful conclusions about human factor, the effectiveness of existing monitoring and enforcing systems and possible future systems regarding enforcement and monitoring of autonomous vehicles (AVs).

A Nationwide Impact Assessment of Automated Driving Systems on Traffic Safety Using Multiagent Traffic Simulations

The objective of this paper is to propose a methodology to estimate nationwide traffic safety impacts of automated vehicle technologies using multi-agent traffic simulations. The influence of three levels of driver trust in the automation system (appropriate, over trust, distrust) is considered in the simulation and takes different transition modes of control between the driver and the system into account. The nationwide estimation of crashes is obtained by projecting results of the simulations using traffic data for three different and representative municipalities. Results indicated that Automated Driving Systems and Advanced Driver Assistance Systems significantly reduced the number of casualties and fatalities compared to manual driving. Simulation results in consideration of the influence of driver trust also found that this reduction may be negatively affected by over- and under-trust parameters. However, even with the introduction of these parameters, the reduction rate was still significant compared to manual driving. The proposed methodology using multi-agent traffic simulations may thus address concerns surrounding the deployment of automated driving systems which is a feature not found in conventional simulations, provide useful insight for interested parties to develop research and policy making strategies that accelerate traffic safety improvements, and to support social acceptance efforts.

Proposal for Prevention of Drowsy Driving-Related Motor Vehicle Accidents in Patients With Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is known to be associated with various health concerns, including sleepiness, fatigue, cognitive dysfunction, diminished quality of life, hypertension, cardiovascular diseases, and stroke. OSA-induced sleepiness at the wheel reduces vigilance and driving performance, which significantly increase the risk of motor vehicle accidents. Sleepiness-induced motor vehicle accidents are characterized by high morbidity and mortality. OSA is a well-established significant risk factor for drowsy driving-related motor vehicle accidents, which can be prevented through appropriate treatment. However, currently no clinical guidelines or regulations are available for evaluation or management of the risk of motor vehicle accidents in patients with OSA in Korea. In this review, we discuss the risk of motor vehicle accidents in patients with OSA, the effects of positive airway pressure therapy as a preventive measure to reduce this risk, and the published recommendations for OSA in other countries with regard to fitness to drive. We propose recommendations for screening, evaluation, and treatment of OSA with regard to the risk of motor vehicle accidents, which would serve as useful practical guidelines for sleep specialists in clinical practice. Further research is warranted to establish optimal strategies for effective improvements in OSA-related traffic safety.

Road Traffic Safety Development Trends in Latvia

The main focus of this article is on the road traffic safety development trends in Latvia. Soon after the regain of independence at the beginning of the 1990s, road traffic safety characteristics in Latvia were the worst in the Latvian history. The increase of car availability and affordability made the car a major road vehicle. The implementation of road safety programmes contributed to essential improvement of road traffic safety in Latvia. The number of road accident fatalities in 2020 compared to 1991 decreased more than sevenfold. Nevertheless, the current Latvian road traffic safety statistics is well below the average level of the EU member states and even the pandemics did not cause similar reduction as in most member states. This indicates that great improvement is still needed. The article shows the Latvian experience in road traffic safety enhancements and discusses the measures to improve road traffic safety.

EPIDEMIOLOGICAL STUDY OF TRAUMA IN A TERTIARY CARE CENTRE IN NORTHWEST INDIA

Objective: Traumatic injuries are a matter of concern worldwide. However, the rapidly changing socio economical dynamics in a developing country like India deeply influence the epidemiology behind trauma. The aim of this study was to document and analyze the epidemiological parameters and characteristics behind trauma victims admitted to our tertiary care centre. Methods: The observational study was carried out over a period of one year (January 2019 to December 2019) enrolling a total of 300 trauma patients. The age, sex, locality, delay in hospitalization, mechanism of injury, sites of injury and outcomes were documented. Results: Injuries occurred predominantly in the 20-40 age group with males being the chief victims. There was a considerable amount of delay in hospitalization ranging from one hour to more than 24 hours while only 7 patients arrived to the emergency within one hour of trauma. Vehicular trauma (54%) was the most common mechanism of injury. Injuries to the extremities (38.6%) and head (28.6%) were the most common sites. A considerable number of patients (45.3%) required care in the intensive care unit. A total of 172 patients required surgical interventions of various kinds and there was a total mortality rate of 6%. Amongst the polytrauma cases, 54 patients (81.8%) required ICU admission, 42 patients (63.6%) required surgical intervention and 6 patients (9.1%) died after admission. Conclusion: The results of this study highlight some of the problems with our existing infrastructure bringing to light the need for stricter enforcement of traffic safety laws and improvement of infrastructure particularly the roadways in rural areas as well as the referral systems. Vehicular trauma should be seen as a public health problem and appropriate interventions should be implemented. Keywords: Trauma, Road Traffic Accidents, Epidemiology, Head injuries

Визначення силової характеристики взаємодії системи пасивної безпеки головного вагона з великим транспортним засобом при зіткненні

One of the priorities of the National Economic Strategy of Ukraine for the Period up to 2030 is the development of the transport sector, in particular railway vehicle renewal, the introduction of high-speed railway passenger transport, and railway traffic safety improvement. The home motor-car trains must be renewed in compliance with new home standards harmonized with European ones, among which one should mention the Ukrainian State Standard DSTU EN 15227, which specifies the passive safety of a passenger train in its emergency collisions with different obstacles. New car designs must provide not only effective up-to-date braking systems to prevent emergency collisions, but also passive safety systems with energy-absorbing devices. The main purpose of these devices is to reduce the longitudinal forces in the intercar connections and the car accelerations to an acceptable level for the three collision scenarios specified in the DSTU EN 15227. The Department of Statistical Dynamics and Multidimensional Mechanical Systems Dynamics, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, developed a passive protection concept for home high-speed passenger trains in emergency collisions by the DSTU EN 15227 scenarios, proposals on the passive protection of a motor-car train head car, and honeycomb designs of lower- and upper-level energy-absorbing devices (EAD 1 and UL EAD, respectively), which are integrated into the head car front part and serve to damp the major part of the impact energy in front collisions with obstacles. This paper considers DSTU EN 15227 Scenario 3: a collision of a reference motor-car train at a speed of 110 km/h at a railway crossing with a large 15 t road vehicle, which is simulated as a large-size deformable obstacle (LSDO). The aim of the paper is to determine the force characteristic of the interaction of energy-absorbing devices mounted on the head car front part with a large road vehicle in a collision to assess the compliance of the proposed passive protection with the normative requirements. Finite-element models were constructed to analyze the plastic deformation of the elements of the EAD 1 – LSDO, UL EAD – LSDO, and EAD 1 – UL EAD –LSDO systems in a collision with account for geometric and physical nonlinearities, steel dynamic hardening as a function of the impact speed, and varying contact interaction between the elements of the systems considered. The studies conducted made it possible to determine the force characteristics of energy-absorbing device – obstacle interaction and the total characteristic of the contact force between two lower-level devices and two upper-level ones as a function of the obstacle center of mass displacement in a collision. The proposed mathematical models and the calculated force characteristics may be used in the study of the dynamics of a reference motor-car train – large road vehicle collision with the aim to assess the compliance of the passive protection of the home head car under design with the DSTU EN 15227 requirements.

Factors Affecting the Acceptance and Willingness-to-Pay of End-Users: A Survey Analysis on Automated Vehicles

The emergence of automated vehicles (AVs) is expected to have a huge impact on traffic safety and environmental improvement. In order to promote the sustainable development of AVs, it is urgent to study the public’s acceptance of and willingness-to-pay for automated vehicles and their influencing factors. Based on a questionnaire survey and descriptive research, this paper investigates the public’s general views on AVs. A psychological model considering technical trust (TT), perceived benefit (PB), perceived risk (PR), and perceived ease of use (PU) was constructed to study the factors that influence the public’s acceptance of and willingness-to-pay for AVs. Logistic regression models based on demographic factors such as monthly income (MI) and driving experience (DE) and psychological factors were established to predict end-users’ acceptance and willingness-to-pay. The accuracy of the two models is 93.2% and 87.9%, respectively. Based on the results, the following policies can be put forward to promote the development of AVs: (1) more information to enhance TT; (2) pricing and easy maintenance based on PU; (3) education and training based on TT and PB; and (4) personalized sales based on DE and MI.

Safety effect analysis of motorcycle V2I collision warning system

Connected vehicle technology can help the driver make decisions, improve awareness of the road environment, and thereby possibly enhance traffic safety. This study explored the impact of a motorcycle vehicle-to-infrastructure (V2I) warning system on road safety through a field trial of a Motorcycle Safety Warning System (MSWS). This study used principal component analysis, K-means, and ordinal logistic regression to explore the effects of the MSWS. After system activation, the road safety level (RSL) improved at 50% of the field trial sites. This study provides a reference for evaluating RSLs through the composite index of this study and verifies that the V2I warning signs of the MSWS provide a certain degree of improvement of motorcycle traffic safety. A V2I system like the MSWS can be used to collect data on driving behaviours in a short period for safety effect analysis, as compared to crash data, which require an extended period. In addition, the traffic behaviour data collected by a V2I system can also be used to identify potential high crash risk locations. The warning signs developed in this study can prevent accidents by alerting drivers who are speeding and at risk of crashes.

Health impacts of bike sharing systems in the U.S

BACKGROUND AND AIM: Bike-sharing systems (BSS) are short-term bike rentals, that can be borrowed from one location and retired to another at the conclusion of the trip. In 2019, the top 10 US largest BSS fleets counted more than 33,500 bikes. To our knowledge, no assessment has quantified the health risk and benefits of multiple BSS in the US. METHODS: This study followed a quantitative health impact assessment approach, to estimate the risks and benefits of BSS. Specifically, we quantified the health impacts related to three exposures: physical activity, air pollution, and traffic incidents. We analyzed all the trips made by BSS systems in the US. Input data on transport, traffic safety, air quality, and physical activity were collated from public records and scientific publications. We modeled the health impacts on adult users related to mortality, disease incidence, disability-adjusted life years (DALYs), and health economic impacts (related to morbidity and mortality). RESULTS:In the US,109,589 BSS trips were made each day. From those 45% substituted car trips, 28% walk trips, and 9% transit trips. Among all travelers, we estimated an annual reduction of 36 million USD in health economic impacts, 737 DALYs, and 4.7 premature deaths related to BSS trips, mainly derived from the increment in physical activity. When we disaggregate the analysis by mode of transport, in all the cases the substitution of public transport, walk and car trips by BSS resulted in more health benefits. In the US, the average estimated health benefit-risk ratio for BSS was 19:1. CONCLUSIONS:BSS in the US provides a health benefit for travelers. Improvements in air quality and traffic safety across the US cities will maximize the health benefits of BSS. This study supports the implementation and expansion of BSS across cities in the US. KEYWORDS: Transport, Bicycling, Bike-sharing systems, Health Impact Assessment, Physical activity, Air Pollution

Health impacts of bike-sharing systems in the U.S.

BackgroundBike-sharing systems (BSS) are short-term bike rentals that can be borrowed from one location and retired to another at the conclusion of the trip. In 2019, 109,589 BSS trips were made each day in the U.S, and half of those in New York City (NYC). AimThis study aims to quantify the health risks and benefits of BSS in the U.S. and NYC. MethodsThis study followed a quantitative health impact assessment approach to estimate the risks and benefits of BSS. Specifically, we quantified the health impacts of physical activity, air pollution, and traffic incidents. We analyzed all the trips made by BSS in the U.S. and NYC. Input data on transport, traffic safety, air quality, and physical activity were collated from public records and scientific publications. We modeled the health impacts on adult users related to mortality, disease incidence, disability-adjusted life years (DALYs), and health economic impacts (related to morbidity and mortality). ResultsWe estimated that in the U.S. BSS trips resulted in an annual reduction of 4.7 premature deaths, 737 DALYs, and 36 million $USD in health economic impacts, mainly derived from the increment in physical activity. In NYC, we estimated an annual reduction of 2 premature deaths, 355 DALYs, and 15 million $USD in health economic impacts. ConclusionBSS in the U.S. and NYC provide a health benefit for bicyclists. Improvements in air quality and traffic safety across U.S. cities will maximize the health benefits of BSS.

Binary search tree-based explicit MPC controller design with Kalman filter for vehicular adaptive cruise system

The adaptive cruise control (ACC) system has received significant attention due to traffic safety improvement, traffic throughput increment, and energy conservation. Model Predictive Control (MPC) has been successfully applied in the control of multi-objective vehicular ACC. However, as a state-feedback policy, MPC requires full state measurement. Meanwhile, the real-time performance of MPC is intractable. This paper proposes to estimate the state value and disturbance value with an extended state Kalman filter to deal with measurement uncertainty. The Kalman filter is based on an augmented state-space model which takes the disturbance term as a new state. To improve real-time performance, this paper suggests employing an explicit MPC (EMPC) based on binary search tree to move the online computational burden of MPC to offline computation by multi-parametric quadratic programming (MPQP). An improved algorithm to solve the MPQP problem offline is proposed, which is initialized discarding the requirement of parameters range, while previous methods need. In the simulated measurement process, the extended state Kalman filter can effectively reduce noise and accurately estimate the value of state and disturbance in the car-following model. Simulations in different scenarios are performed to test the effectiveness of the proposed ACC controller. Results show that the proposed EMPC for the ACC system can improve the real-time performance of the MPC with little loss of performance. On average, the EMPC via binary search is 95.8 times faster than the MPC with the same parameters as EMPC for the studied ACC system. And it has better overall performance compared with the ACC with collision avoidance (CA-ACC) method.

Study on the Impact of Traffic Accidents in Key Areas of Rural Roads

In recent years, the proportion of rural road fatalities in the country is gradually increasing, among which the traffic safety problems are particularly prominent in the town-rural area and the town-center area. Based on the relevant accident data in Hunan Province in recent years, the chi-square test was conducted to obtain the correlation degree between each risk factor and accident severity based on gender stratification. Then, a binary logistic model was established to obtain the significant factors that affect the accident severity in the town-rural area and the town-center area, respectively. Based on the significant factors, relevant safety improvement measures were proposed for the key areas. The results show that severe accidents were significantly related to single-vehicle factors, motorcycle factors, and intersections factors in the town-rural area. In the town-center area, severe accidents were significantly related to elderly age, single-vehicle factors, and nighttime factors. The study obtained the risk factors in key areas, which can provide a reference for the improvement of traffic safety in key areas of rural roads, to ensure the safety and sustainability of rural traffic.

Identification and spatiotemporal evolution analysis of high-risk crash spots in urban roads at the microzone-level: Using the space-time cube method

The problem of urban crashes brings huge challenges and threats to local police and governments, especially in many cities in developing countries such as China. To reduce the frequency and severity of urban crashes, the local government in China has gradually taken interest in conducting detailed actions of traffic safety improvement at the microzone-level. Therefore, the primary goal of this study is to try a new method in spatiotemporal data mining techniques, the space-time cube method, to find high-risk crash spots at the spatiotemporal level and to obtain their spatiotemporal evolution patterns. The cumulative frequency curve method was performed to identify high-risk crash spots, and the contributory factors of forming these spots were analyzed by the latent class analysis method. The results showed that: (1) key parameters’ selection is crucial in the space-time cube construction; (2) the exit ramp gore point in interchanges, intersections, and entrances of neighborhoods were prone to have many high-risk crash spots at the spatiotemporal scale; and (3) locations with consecutive, persistent, and sporadic hotspots patterns need different risk monitoring strategies and traffic safety improvement. The feasibility and advantages of the space-time cube method in hotspots identification at the microzone-level were confirmed.

Pedestrian crossing volume estimation at signalized intersections using Bayesian additive regression trees

Pedestrian crossing volume is one of the most important variables used to retime and optimize the signal timing plans for traffic delay migration and traffic safety improvement at signalized intersections. However, most of the existing studies only focus on long-term pedestrian volume estimation for planning purposes. To bridge the research gap, this study applied a Bayesian Additive Regression Trees (BART) model to estimate the short-term pedestrian crossing volume at signalized intersections equipped with pushbutton devices. Pedestrian-related traffic controller event-based data used as the time-dependent variables representing the temporal trend of pedestrian crossing volume in conjunction with point-of-interest (POI) data and transit trips are chosen as the inputs of the BART model. Seventy signalized intersections from the Pima County region are selected to collect data for calibrating and validating the developed model. When compared with ground-truth data, the proposed method has an R-squared of 0.83, 0.81, and 0.71 for 60 min, 30 min, and 15 min intervals of pedestrian crossing volume, respectively. To further evaluate the performance of the proposed method, the proposed method is used in comparison to two traditional methods (stepwise linear regression and Random Forest). The comparison results show that the BART model is superior to the other two models for hourly pedestrian crossing volume estimation. The evaluation results show that the proposed method can accurately estimate pedestrian crossing volume and provide valuable information for signal retiming.

Estimation of Traffic Safety Improvement Effect of Forward Collision Warning (FCW)

Estimation of Traffic Safety Improvement Effect of Forward Collision Warning (FCW)

Evolution of requirements to state of order of automotive tires for traffic safety

The paper presents the results of a study of the influence of the amendment of the requirements to the technical state of order of motor vehicles, specifically, to the design of the tires used on the front and rear axles of motor vehicles on the motor traffic safety. It has been determined that newly developed requirements aim on the reduction of the difference of the traction between the front and the rear axle for more prompt response of the braking mechanisms and improved braking efficiency. It has been demonstrated that the implementation of the design requirements to vehicles developed in 2010 an 2013 allows for reduction of the accident rates of motor vehicles using different tire types by 3%. Further tightening of the operational requirements to motor vehicles in this direction has a reserve allowing for max. 1% of further reduction of the accident rate whereafter the reserve of the traffic safety improvement will be deemed exhausted.

Driving locus of control: The Czech adaptation

Objectives. This study attempts to introduce the Driving Locus of Control (DLoC), a method focused on the internal or external source of attribution of the driving behaviour, to the Czech context. This study also relates DLoC to attitudes towards autonomous vehicles (AVs). Participants and setting. Out of the general population, 59 inquirers personally interviewed (CAPI) 1 065 respondents (49% women) in the age range between 15 and 92 years (M = 50, SD = 17). The respondents were sampled via multistage random sampling procedure, based on the list of addresses in the Czech Republic. Hypotheses. The authors hypothesised to replicate the original two-factor structure of the DLoC Scale and that the higher levels of internal DLoC result in not considering the improvement in traffic safety as the AVs replace human drivers. Statistical analysis. Confirmatory factor analysis was used to analyse the factor structure of DLoC Scale. Hypotheses related to the empirical validity of the method were assessed via structural equation modelling. The reliability of DLoC Scale was calculated in terms of internal consistency (McDonald coefficient). Results. Confirmatory factor analysis revealed reasonably good support for structural validity of the one-dimensional DLoC-CZ15 factor model (χ2 = 426.967, df = 90, CFI = 0.964, TLI = 0.958, SRMR = 0.066, RMSEA = 0.065). In addition, the one-dimensional DLoC-CZ15 factor model showed acceptable internal consistency - ω = 0.9 (95% CI [0.89, 0.91]). The structural equation modelling found a relationship between DLoC and some of the items capturing attitudes towards AVs, too. Study limitations. The analysed data were obtained via interviews between respondents and inquirers. As a result, the study does not contain indicators of empirical validity measured by a methodologically different approach, such as an observation of driving behaviour.

Efektivitas Pelaksanaan Program Peningkatan Keselamatan Lalu Lintas Oleh Dinas Perhubungan Kota Padang

This research supports the design of a program to improve traffic safety by the Padang City Transportation Department. This program is an effort made by the Department of Transportation to replace the number of traffic accidents that are felt to be very high. Efforts in the future are directed at countermeasures that support efforts to foster, improve, regulate and enforce the law. This program is guided by Law Number 22 Year 2009 Concerning Traffic and Road Transportation Safety and Security Culture. This study used descriptive qualitative method. Data collection techniques used were interviews and documentation. The results showed how the implementation of the traffic safety improvement program conducted by the Padang City Transportation Office has not been going well. It can be seen from the meeting that the objectives of this program have not been successful because the number of accidents in the City of Padang has increased, the acquisition of resources in the implementation of this program has not well approved because the specified budget and human resources from the Padang City Transportation Office are still classified as inadequate because the demands from the Transportation Office are very large for the Padang City area. The internal process in the implementation program has been well approved in the process of communication between employees and a high commitment in managing transportation in the city of Padang. Strategic constituency satisfaction has not been well approved because it involves community participation in program implementation and self-safety.

Patterns of Pediatric Facial Fractures.

The aim of this study was to assess patterns of maxillofacial trauma in the pediatric population in Atlanta. This information is important to help guide management and allocate resources for treatment of maxillofacial injuries at Children's Healthcare of Atlanta (CHOA). This study was a retrospective chart review of children who presented from 2006 to 2015. Inclusion criteria were: (1) age 18 years old or younger, (2) presentation to emergency department, (3) diagnosis of maxillofacial fractures, and (4) evaluation by Oral and Maxillofacial Surgery, Otolaryngology, or Plastic Surgery services. Medical records were reviewed to record demographic, mechanism of injury, fracture location, and yearly incidence of injury. Descriptive statistics were computed to summarize findings and overall trends. During the study period, 39,833 patients were identified. Of them, 1995 met the inclusion criteria. The majority were male (n = 1359, 68%) with an average age of 9.4 years old (range of 1 month to 18 years old). Mechanisms of injury were motor vehicle collisions (MVC) (n = 597, 29.9%), fall (n = 565, 28.3%), sports injury (n = 317, 15.9%), pedestrian struck (n = 215, 10.8%), assault/abuse (n = 204, 10.2%), other (n = 81, 4.1%), or gunshot wound (n = 16, 0.8%). Fracture sites were mandible (n = 519, 26%), complex (n = 479, 24%), nasal (n = 419, 21%), dentoalveolar (n = 279, 14%), orbital (n = 259, 13%), and maxilla (n = 40, 2%). Males had a higher incidence of assault than females (n = 185, 91% of assaults). The incidence of maxillofacial trauma increased with age with a peak incidence in 13 to 16-year-olds (n = 566, 28.3%). During the years examined, there was an upward trend in MVCs as the etiology with a peak incidence of facial fractures due to MVCs occurring in 2015. All other mechanisms remained constant during this time period. There was an increase in pediatric facial fractures secondary to motor vehicle collisions from 2007 to 2015 despite improvements in regulations, traffic safety, and technology.