Institute For Traffic Accident Research And Data Analysis Research Articles

Driving Ambulances Safely: Findings of Ten Years of Japanese Ambulance Crash Data

Objective Rules and regulations for ambulance operations differ across countries and regions, however, little is known about ambulance crashes outside of the United States. Japan is unique in several aspects, for example, routine use of lights and sirens during response and transport regardless of the urgency of the case and low speed limits for ambulances. The aim of this study was to describe the incidence and characteristics of ambulance crashes in Japan. Methods We retrospectively analyzed data from the Institute for Traffic Accident Research and Data Analysis (ITARDA) that include all traffic crashes resulting in injury or death in Japan. The study included all ambulance crashes from 2009 to 2018. We compared crashes that occurred during emergency operations with lights and sirens (i.e., when responding to a call or transporting a patient) to those that occurred during non-emergency operations without lights or sirens. We also used data on total number of ambulance dispatches from the Japanese Fire and Disaster Management Agency to calculate ambulance crash risk. Results During the 10-year period, we identified a total of 486 ambulance crashes out of 59,208,761 ambulance dispatches (0.82 in every 100,000 dispatches or one crash for every 121,829 dispatches) that included two fatal crashes. Among all ambulance crashes, 142 (29.2%) occurred during emergency operations. The incidence of ambulance crashes decreased significantly over the 10-year period. Ambulance crashes at an intersection occurred more frequently during emergency operations than during non-emergency operations (72.5% vs. 58.1%; 14.4% difference, 95% CI 5.0–22.9). Conclusions Ambulance crashes occurred infrequently in Japan with crash rates much lower than previously reported crash rates in the United States. Ambulance crashes during emergency operations occurred more frequently at intersections compared to non-emergency operations. Further investigation of the low Japanese ambulance crash rates could provide opportunities to improve ambulance safety in other countries.

Association of Impact Velocity with Serious-injury and Fatality Risks to Cyclists in Commercial Truck-Cyclist Accidents.

This study aimed to clarify the relationship between truck-cyclist collision impact velocity and the serious-injury and fatality risks to cyclists, and to investigate the effects of road type and driving scenario on the frequency of cyclist fatalities due to collisions with vehicles. We used micro and macro truck-cyclist collision data from the Japanese Institute for Traffic Accident Research and Data Analysis (ITARDA) database. We classified vehicle type into five categories: heavy-duty trucks (gross vehicle weight [GVW] ≥11 × 103 kg [11 tons (t)], medium-duty trucks (5 × 103 kg [5 t] ≤ GVW < 11 × 103 kg [11 t]), light-duty trucks (GVW <5 × 103 kg [5 t]), box vans, and sedans. The fatality risk was ≤5% for light-duty trucks, box vans, and sedans at impact velocities ≤40 km/h and for medium-duty trucks at impact velocities ≤30 km/h. The fatality risk was 6% for heavy-duty trucks at impact velocities ≤10 km/h. Thus, the fatality risk appears strongly associated with vehicle class and impact velocity. The results revealed that a 10 km/h reduction in impact velocities could mitigate the severity of cyclist injuries at impact velocities ≥30 km/h for all five vehicle types. The frequency of cyclist fatalities at intersections with traffic signals involving heavy-duty trucks was significantly higher during daytime than that at nighttime. Fatalities involving vehicles making a left turn generally increased with vehicle weight. The frequency of cyclist fatalities involving vehicles making a left turn was the largest for heavy-duty trucks both during daytime (67.6%) and at nighttime (52.3%).

Features of fatal injuries in older cyclists in vehicle–bicycle accidents in Japan

ABSTRACTObjective: The purpose of this study was to identify and better understand the features of fatal injuries in cyclists aged 75 years and over involved in collisions with either hood- or van-type vehicles.Methods: This study investigated the fatal injuries of cyclists aged 75 years old and over by analyzing accident data. We focused on the body regions to which the fatal injury occurred using vehicle–bicycle accident data from the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. Using data from 2009 to 2013, we examined the frequency of fatally injured body region by gender, age, and actual vehicle travel speed. We investigated any significant differences in distributions of fatal injuries by body region for cyclists aged 75 years and over using chi-square tests to compare with cyclists in other age groups. We also investigated the cause of fatal head injuries, such as impact with a road surface or vehicle.Results: The results indicated that head injuries were the most common cause of fatalities among the study group. At low vehicle travel speeds for both hood- and van-type vehicles, fatalities were most likely to be the result of head impacts against the road surface.The percentage of fatalities following hip injuries was significantly higher for cyclists aged 75 years and over than for those aged 65–74 or 13–59 in impacts with hood-type vehicles. It was also higher for women than men in the over-75 age group in impacts with these vehicles.Conclusions: For cyclists aged 75 years and over, wearing a helmet may be helpful to prevent head injuries in vehicle-to-cyclist accidents. It may also be helpful to introduce some safety measures to prevent hip injuries, given the higher level of fatalities following hip injury among all cyclists aged 75 and over, particularly women.

SUVと中型セダン型乗用車の前面衝突事故における乗員の傷害内容の分析

Recently, AACN (Advanced Automatic Collision Notification) that presupposed cooperation with emergency life-saving organizations is expected. Therefore, emergency life-saving organizations must recognize injury speciation of patients, as quickly as possible. So, the author tried the traffic accident analyzing method by statistical data analysis from combing analysis items analysis items for main site of injury and analysis items for injury contents (indicated in the traffic accident statistics vote by Japanese National Police Agency). And furthermore it is necessary to improve the safety of vehicles not only for same class collisions but also for collisions between vehicles of different types (e.g., between SUVs and sedans). In this study, the author applied the method of analysis as described above for frontal collision between SUVs and middle sedans, and analyzed using statistical data stored in ITARDA (Institute for Traffic Accident Research and Data Analysis). In the case of fatal or severe injuries, it is shown that the component rate of chest fracture of middle sedan drivers is higher than that of SUVs. It is supposed that the difference in these rates is caused by the vertical offset configuration between the frames of the two different types of vehicles when they crash into each other.

Association of Impact Velocity with Risks of Serious Injuries and Fatalities to Pedestrians in Commercial Truck-Pedestrian Accidents.

This study aimed to clarify the relationship between truck-pedestrian crash impact velocity and the risks of serious injury and fatality to pedestrians. We used micro and macro truck-pedestrian accident data from the Japanese Institute for Traffic Accident Research and Data Analysis (ITARDA) database. We classified vehicle type into five categories: heavy-duty trucks (gross vehicle weight [GVW] ≥11 × 103 kg [11 tons (t)], medium-duty trucks (5 × 103 kg [5 t] ≤ GVW < 11 × 103 kg [11 t]), light-duty trucks (GVW <5 × 103 kg [5 t]), box vans, and sedans. The fatality risk was ≤5% for light-duty trucks, box vans, and sedans at impact velocities ≤ 30 km/h and for medium-duty trucks at impact velocities ≤20 km/h. The fatality risk was ≤10% for heavy-duty trucks at impact velocities ≤10 km/h. Thus, fatality risk appears strongly associated with vehicle class. The results also revealed that a 10 km/h reduction in impact velocities could mitigate the severity of pedestrian injuries at impact velocities ≥30 km/h for all five analyzed vehicle types. Therefore, serious injuries and fatalities to pedestrians could be decreased by the development and deployment of collision mitigation systems (CMSs) to all vehicles, including to commercial trucks, because CMSs can detect pedestrians in even severe conditions, such as when the drive's view is obstructed, and can reduce the impact velocity. The present results indicate that CMS design specifications should differ between vehicle types because of the strong dependence of seriousinjury and fatality risks on vehicle type.

Development of injury prediction models for advanced automatic collision notification based on Japanese accident data

ABSTRACTIn this paper, injury prediction models for estimating serious injury risk of occupants were developed based on accident data available in the Japanese statistical DB. Four types of model by crash direction (frontal crash model, near-side crash model, far-side crash model, rear-end crash model) were developed. These models were developed by using a logistic regression modelling technique based on data from Japanese ITARDA (Institute for Traffic Accident Research and Data Analysis) police-reported statistics, a large database for the last decade. Risk factors of the model are delta-V, belt use, multiple impact crash and occupant's age. Serious injury risk for four crash directions was estimated by the model. A comparison has been done between estimated serious injury risk and actual injury of Japanese ITARDA in-depth accident data (micro-data). The results show that the injury prediction model has a possibility for predicting injury risk based on onboard data and its application for post-crash safety.

交通事故統計分析から推定する道路形状別リスク評価（第 2 報）

As vehicles existing many types, for example passenger vehicles or trucks, buses, there are many type roads, for example narrow country road or wide arterial highway, expressway. Therefore, it is important to implement countermeasures of safety in responding to road environment for constructing high safety road traffic society. In the former study, the author classified road types by depended on the road environment, for example the road width or with or without of centerlines, divided roads or non-divided roads and clarified characteristics of traffic accident types or violations of laws by road type using traffic accident integrated data stored at Institute for Traffic Accident Research and Data Analysis (ITARDA). However, it is difficult to construct specific countermeasures for traffic safety using factors only traffic accident types or violations of laws. So, it is important to clarify other factors, for example constitutions of accident vehicle type or hazard perception velocity of accident drivers, high-accident time zone. In this study, the author analyzed constitutions of vehicle type or hazard perception velocity, time zone by road types, using traffic accident integrated data stored at ITARDA, and clarified characteristics of traffic accident situations of each road types.

交通事故統計分析から推定する道路形状別リスク評価

It is important to implement countermeasures of safety in responding to road environment for constructing high safety road traffic society. As well as vehicles existing many types, for example passenger vehicles or trucks, buses, there are many type roads, for example narrow country road or wide highly traveled highway, expressway. And characteristics of road user or environment are different by road type. There are many pedestrians on urban area road, and velocity of vehicles on suburban area road are high-speed. Therefore, it is assumed that characteristics of traffic accidents are different by road type. So, the author tried the risk evaluation by clarifying characteristics of traffic accidents of several road type, by analyzing the traffic accident data stored in Institute for Traffic Accident Research and Data Analysis (ITARDA). In populated-urban area, intersection without center line B-class, the frequency of vehicle to bicycle collision by un-confirmation of forward or right, left is high. And in non-urban area, non-intersection divided road B-class, the frequency of rear-end collision by forward careless (inattentive driving) is high. As described above, the risk of traffic accident type or violations of laws seen with a high frequency, is different by road type.

Analysis of facial injuries requiring ophthalmological care due to frontal vehicle collisions

Motor vehicle collisions are responsible for a large number of ocular injuries. Although ocular injuries require an early ophthalmological examination at the time of trauma to detect any type of ocular dysfunction, some ophthalmological abnormalities are not detected after the facial injury owing to failure of referral ophthalmologists. This study aimed to investigate the prevalence of requiring ophthalmological care by evaluating the patterns and severity of ocular and severe facial injuries from real-world vehicle collisions in Japan. We collected data on vehicle passengers with any facial injuries who were involved in frontal collisions. Data were obtained from in-depth data records from the Institute for Traffic Accident Research and Data Analysis (ITARDA), Japan from 1993 to 2005. Collision information and victims’ medical data were reviewed. The 226 victims had a mean age of 33.3 ± 14.9 years with an equivalent barrier speed of 35.2 ± 13.0 km/h. Thirty (13.3%) victims suffered ocular injury or fractures in the upper or middle face (OIFF). Victims with OIFF had a significantly higher severity of injuries, especially in the face and lower extremities, and suffered from a higher speed of collisions than those without OIFF (p&lt;0.001). Victims wearing seat belts had a significantly lower prevalence of having OIFF than those not wearing seat belts. Most of the victims with OIFF (29/30) were involved in collisions without deployment of airbags. To prevent severe ocular injuries, correct use of seat belts with airbag deployment is required. Additionally, the present study enhances that more victims with OIFF are cared for by ophthalmologists immediately after the collision, improving their quality of life and preventing conflicts owing to inadequate medical management.

Relation between vehicle travel velocity and pedestrian injury risk in different age groups for the design of a pedestrian detection system

The vehicle travel velocity at the moment of pedestrian contact is considered to be an important parameter that affects the accident outcome. To reduce the vehicle-to-pedestrian travel velocity, a pedestrian detection system using a sensor in a vehicle could be an effective countermeasure. The specifications of the pedestrian detection system will need to be designed properly based on real-world accident situations. Then, the purpose of this study is to clarify the relation between vehicle travel velocity and pedestrian injury severity or fatality risk in traffic accident analyses in order to propose specifications of a pedestrian detection system. We analyzed the relation using the Institute for Traffic Accident Research and Data Analysis (ITARDA) database for 2009 in Japan, considering different factors including a vehicle type and pedestrian age in actual traffic accidents. The results indicate that the percentage risk of fatality was consistent between sedans and light passenger cars at every vehicle travel velocity, rising sharply at a vehicle travel velocity of 40km/h. Meanwhile, in car-to-pedestrian accidents involving sedans and light passenger cars, pedestrians aged 60 and over faced the higher risk of fatality, which increased rapidly at the vehicle travel velocity of 40km/h. Therefore, the present study proposes that the specifications of the pedestrian detection system should be designed so that the vehicle travel velocity in traffic accidents could be reduced to 30km/h or lower, when we consider the decrease of fatality.

Risks of Serious Injuries and Fatalities of Cyclists Associated with Impact Velocities of Cars in Car-Cyclist Accidents in Japan.

The main purpose of this study is to define the relationship between the car impact velocity and serious injury risk or fatality risk of cyclists. The authors investigated the risks of serious injuries and fatalities of cyclists using vehicle-cyclist accident data from the database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. The vehicle types considered are sedans, mini vans, box vans, light passenger cars and light cargo vans. The results revealed that a 10-km/h decrease in the impact velocity could reduce the severe injury risk and fatality risk for impact velocities of 40 km/h or higher. Specifically, when the impact velocity was less than or equal to 30 km/h, the serious injury risks were less than 21% and the fatality risks were less than or equal to 1% for the above listed vehicle types. Therefore, if the Collision Damage Mitigation Braking System (CDMBS) equipped vehicles can perform its functions effectively so as to reduce the impact velocities, then cyclist injuries will likely be significantly reduced. Another purpose of this study is to assess the effect of wearing a helmet for protection of the cyclist's head. Impact experiment results showed that the measured head injury criterion (HIC) with helmets are lower than that of head-form impactor without a helmet, reducing the HIC by 57%.

Characteristics of collision damage mitigation braking system for pedestrian protection

The vehicle travel velocity at pedestrian contact is considered to be an important parameter that affects the crash outcome. To reduce vehicle/pedestrian impact velocity, a collision damage mitigation braking system (CDMBS) using a sensor for pedestrian protection could be an effective countermeasure. The first purpose of this study is to clarify the relation between vehicle travel velocity and pedestrian injury severity due to differences in pedestrians’ ages in actual traffic accidents. The accident analyses were performed using vehicle-pedestrian accident data in 2009 from the database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. The result revealed that the fatality risk became higher with the increase in vehicle travel velocity. The second purpose of this study is to determine the safety performance of production vehicles equipped with the CDMBS for pedestrian protection. It was found that the CDMBS was highly effective in reducing the impact velocity from 50 km/h (vehicle travel velocity) to below 17 km/h, that could result in a significant decrease in fatality risk to be 2% or less. Additionally, the authors investigated a detectable zone with respect to a pedestrian’s position in relation to the vehicle. It was shown that the detectable zones for production vehicles tested were limited to be inside the vehicle front width.

Features of Fatal Pedestrian Injuries in Vehicle-to-Pedestrian Accidents in Japan

The number of traffic deaths in Japan was 4,612 in 2011. Looking at the road accident fatalities, it revealed that pedestrians accounted for the highest number in 2011 (1,686, 36.6%). To develop safety countermeasures to decrease the severity of injuries and to reduce the number of deaths in traffic accidents, the detailed characteristics of pedestrian injury in vehicle-to-pedestrian crashes are necessary. The purpose of this study is to understand the scenarios of vehicle accidents in which pedestrians suffer fatal injuries. In the present study, we investigated the characteristics of pedestrian injuries in fatal crashes from accident analyses and compared them to head injury severity levels in impact tests against a road pavement and vehicle contact surfaces. In the accident analyses, we investigated the main body regions injured, that is, the most serious extent of injuries over the whole body of pedestrians by using macro vehicle-pedestrian accident data from database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) of Japan. In comparing the differences in injury frequencies for various body regions between 1999 and 2009, it is noted that the frequencies of pedestrian fatalities due to head injuries were significantly reduced. The result indicated that even though head injuries were the most frequent cause of pedestrian fatalities in traffic accidents, the introduction of pedestrian head protection regulation in Japan in 2005 could be considered effective in reducing fatal head injuries. On the other hand, the frequencies of pedestrian fatalities due to hip injuries increased significantly in sedans, light passenger cars, and light cargo vans. Using the macro accident data in 2009, we investigated the frequency of pedestrian fatalities by gender, age group, vehicle travel speed, and fatal head injuries due to vehicle impacts or road pavement impacts. The results also indicated that the frequencies of female pedestrian fatalities due to hip injuries were significantly higher than those of males. Additionally, the results showed that the frequency of pedestrian fatalities due to hip injuries for the age group of over 65 years was significantly higher than that of the industrial age group (aged 13-59). Focusing on the frequency of pedestrian fatalities due to hip injuries in all age groups, vehicle travel speed appeared likely not to be an extremely important factor in increasing fatal hip injuries. In examining the differences in the frequency of fatal head injuries due to contacts with vehicles or road pavements, it is noted that injury frequency in crashes involving vehicles travelling at high speeds were significantly higher than those at lower speeds for pedestrians over 60 years of age. Focusing on head injury severity levels in impact tests against a road and vehicle surfaces using an adult pedestrian headform impactor, the impacts against a road pavement (HIC 6525) was considered to be more severe than those against vehicle front components with high stiffness (HIC from 2600 to 4032). Language: en

Benefit Estimation of a Lane Departure Warning System using ASSTREET

It is known that the collisions caused by lane departure events account for range of percentages among the countries studied. To help prevent such collisions, the Lane Departure Warning (LDW) system has started to be introduced in production vehicles, but there is little research on its benefits and limitations so far. In this paper we performed an in-depth analysis of the collisions and driver-related essential variables for the lane-departure collision scenarios and demonstrated the benefit estimation process. The benefit of the LDW system is estimated by comparing lane departure events when the vehicle has no LDW, and how they change with the addition of LDW. The event without LDW was modeled in 5 phases: (1) before departure, (2) starting of the departure, (3) departed the lane, (4) at the impact with an object, and, (5) after the impact. An extensive analysis was conducted of traffic crash data compiled by the Institute for Traffic Accident Research and Data Analysis (ITARDA). The results of this analysis were used to create models of each phase of an LDW event. The Advanced Safety System & Traffic REaltime Evaluation Tool (ASSTREET), which is based on Monte-Carlo Simulation, was then used to simulate a variety of collision types. The results of these simulations were validated by comparing the distributions of fatality, serious injury, minor injury and no injury that they generated to crash statistics for Japan. Then, the effect of the LDW system was added to the lane departure events. The drivers' response delay to the LDW and the possible reactions were measured in a driving simulator test. The comparison between events with and without LDW clearly shows which cases could be prevented by the use of LDW and the ones that could not be avoided, thereby, providing us with important guidelines to improve the system performance. Language: en

Injury severity of occupants in lateral collisions in standard and small vehicles: Analysis of ITARDA's in-depth investigation data

A retrospective analysis was performed to investigate the differences in occupant injury characteristics between standard and small vehicles in lateral collision. From the in-depth data of the Institute for Traffic Accident Research and Data Analysis (ITARDA) from 1993 to 2003, data were collected for 331 adults who were front-seat occupants involved in single lateral motor vehicle collisions. The accident information, the subjects’ medical data and the anatomical injury severity scores were examined. The involved passenger vehicles were classified as small or standard. Seatbelts were effective in decreasing the head–neck injury severity of far-side occupants of standard vehicles, but in small vehicles, no significant benefit was observed. In standard vehicles, far-side occupants suffered less severe injuries than near-side occupants, but this trend was not apparent in small vehicles. These differences may result from the smaller interior space of the smaller vehicles.