The most difficult at-fault fatal crashes to avoid with current active safety technology.

OBJECTIVE: We studied which current fatal at-fault crashes would occur despite the most advanced current active safety devices (up to SAE level 2 of driving automation) and how frequent these crashes would be. METHODS: We carried out a cross-sectional study of passenger cars that were first registered during the period 1st January 2010 to 31st December 2017 in Finland. To gain the true exposure for these cars, we accessed the national Vehicular and Driver Data Register to obtain the mileage information and the registration count for the study period of 2010-17. Similarly, we accessed the registry of Finnish road accident investigation teams and included all fatal at-fault crashes among the cars in our study for the same period. We used a real world reference technology for each active safety system in our analysis and chose one car brand as an example. This gave us exact system specifications and enabled testing the operation of the systems on the road. We performed field tests to gain further information on the precise operation of the safety systems in different operating conditions. Finally, we gathered all information on the studied active safety systems and analyzed the investigated at-fault fatal crashes case-by-case using our four level method. RESULTS: Cars in our study were the primary party in 113 investigated fatal accidents during the years 2010-17. In 87 of the accidents, the leading cause of death was the injuries due to the crash, and these cases were classified as "unavoidable" (n = 58, 67 %), "avoidable" (n = 26, 30 %) or unsolved (n = 3, 3 %). Of the 58 "unavoidable" crashes 21 (36 %) were suicides, 21 (36%) involved active driver input which would have prevented the safety system operation, 15 (17 %) featured circumstances beyond the safety system performance and in one loss-of-control crash the driver had disabled the relevant safety system (electronic stability control). The registration years of the cars in our study (2010-17) totaled 3,772,864 and during this period, the cars travelled 75.9 billion kilometers. The crash incidence of the "unavoidable" at-fault fatal crashes was 0.76-0.80 fatal crashes per billion kilometers and 15-16 fatal crashes per million registration years. CONCLUSIONS: We calculated a crash incidence for the "unavoidable" crashes which was 20-27% smaller than the observed crash rate of ESC-fitted passenger cars in our previous study. We concluded that suicides, active driver input until the crash, and challenging weather and road conditions are the most difficult factors for current active safety systems. Our analysis did not account for issues such as system usability or driver acceptance and therefore our results should be regarded as something that is currently theoretically achievable. However, the observed incidence is a good reference for automated driving development and the crash rate of automated cars.

Crash risk of ESC-fitted passenger cars.

Objective: We examined both fatal and injury at-fault crashes of a population of passenger cars fitted with electronic stability control (ESC). Crash rates were calculated in relation to both registration years and mileage. Crash rates were also calculated for a non-ESC car population and crash rate ratios were calculated to compare the crash risk between ESC-fitted and non-ESC-fitted passenger cars. Methods: Passenger car models with and without ESC were identified (ESC-equipped cars: 3,352,813 registration years; non-ESC-equipped: 5,839,946 registration years) and their vehicle information for the period 2009-2013, including mileage (ESC-equipped vehicles: 89.3 billion kilometers; non-ESC-equipped: 72.4 billion kilometers), was drawn from the national Vehicular and Driver Data Register. The registry of Finnish road accident investigation teams was accessed and all fatal at-fault crashes among the cars in the study populations (ESC 97; non-ESC 377) for the period 2009-2013 were analyzed. The motor insurance database includes at-fault crashes leading to injuries and was utilized for analyses (ESC: N = 8,827, non-ESC: N = 21,437). Crash rates and crash rate ratios were calculated to evaluate crash risk of both ESC-equipped and non-ESC-equipped passenger cars. Poisson regression was used to model crash involvement rate ratios both per registration year and per mileage for vehicles with ESC and without ESC, controlling for age and gender of the vehicle owner and vehicle mass. Results: Passenger cars fitted with ESC showed lower crash rates than non-ESC-equipped cars in all crash types studied. In general, the difference in crash rates between ESC-equipped and non-ESC-equipped vehicles was greater when the crashes were compared to the mileage rather than registration years. The mileage-proportional crash rate of ESC-equipped cars was 64% (95% confidence interval, 61%; 67%) lower in run-off-road crashes resulting in injury and as much as 82% (65%; 91%) lower in fatal run-off-road crashes when suicides and disease attacks were not taken into account. Conclusions: Our results show that modern passenger cars provide a significant crash risk reduction, which depends on both ESC and passive safety features introduced. Results also show that exposure evaluation in terms of registration years (or vehicle population) instead of true mileage can provide an overly pessimistic view of the crash risk.

Airbag deployment-related eye injuries.

OBJECTIVE: We studied the correlation between airbag deployment and eye injuries using 2 different data sets. METHODS: The registry of the Finnish Road Accident (FRA) Investigation Teams was analyzed to study severe head- and eyewear-related injuries. All fatal passenger car or van accidents that occurred during the years 2009-2012 (4 years) were included (n = 734). Cases in which the driver's front airbag was deployed were subjected to analysis (n = 409). To determine the proportion of minor, potentially airbag-related eye injuries, the results were compared to the data for all new eye injury patients (n = 1,151) recorded at the Emergency Clinic of the Helsinki University Eye Hospital (HUEH) during one year, from May 1, 2011, to April 30, 2012. RESULTS: In the FRA data set, the unbelted drivers showed a significantly higher risk of death (odds ratio [OR] = 5.89, 95% confidence interval [CI], 3.33-10.9, P = 2.6E-12) or of sustaining head injuries (OR = 2.50, 95% CI, 1.59-3.97, P = 3.8E-5). Only 4 of the 1,151 HUEH patients were involved in a passenger car accident. In one of the crashes, the airbag operated, and the belted driver received 2 sutured eye lid wounds and showed conjunctival sugillation. No permanent eye injuries were recorded during the follow-up. The calculated annual airbag-related eye injury incidence was less than 1/1,000,000 people, 4/100,000 accidents, and 4/10,000 injured occupants. CONCLUSIONS: Airbag-related eye injuries occurred very rarely in car accidents in cases where the occupant survived and the restraint system was appropriately used. Spectacle use did not appear to increase the risk of eye injury in restrained occupants.

Traffic and Criminal Behavior of Adults with Attention Deficit-Hyperactivity with a Prospective Follow-Up from Birth to the Age of 40 Years.

OBJECTIVE: The purpose of this study was to investigate whether individuals with attention deficit-hyperactivity disorder (ADHD) followed up to age 40 have a higher mortality, more involvement in criminal behavior, increased traffic accidents, and frequency or registered violations against traffic rules or whether they have been more frequently victims to crimes. METHODS: The ADHD cohort (N = 122) born in 1971-1974 was isolated at the age of 9 years from the base cohort of 865 children who had known risk factors at birth and were still alive at the age of 5 years. Ninety-four healthy individuals born during the same years served as control subjects. None of the individuals with ADHD had used psychostimulants before their adolescence. The follow-up data were available from the newborn period until the ages of 5 and 9 years. At the ages of 16 and 30, the data were collected via questionnaire. For this study, the national police registers (last 5 years) were examined for traffic violations, crimes, or being an object of a criminal act when the persons reached the age of 40 years. RESULTS: Ten men and one woman with ADHD but none of the controls had died by the age of 40. Three died of disease-related incidents, and 8 (13%) died of abnormal causes such as suicide (3), traffic accident (2), substance abuse (2), or violence (1). During the follow-up period, individuals with ADHD had been involved in violent behavior or economic criminality more frequently than the control subjects. They were also more commonly victims of criminal acts. No difference was found in traffic citations between those with ADHD and control subjects (at 35-40 years) when all traffic crimes were considered. A difference was not observed in the frequency of traffic accidents. However, there was a significant difference in drunk driving (at the ages of 30 and 35-40) and the number of persons without a driver's license. DISCUSSION: Subjects with ADHD showed an elevated risk of being involved in criminality and had a higher risk of dying before the age of 40 years. The early detection of ADHD in childhood and appropriate treatments and family support may decrease criminality and save both money and human distress.