Formulation of Driver Judgment Process around Curves for Deviated State Detection

The objective of this study is to propose indices that detect deviated states of drivers during driving considering their judgment process and using a road environment and natural driving behavior database. To this end, we focus on curved roads because as road curvature changes continuously drivers need to adapt their behavior to not go wide of the lane or the road. The drivers’ speed choice behavior around curve situations was focused upon, and a speed choice process was formulated. Moreover, the validity of the formulated speed choice behavior in curve situations was examined using the real vehicle and the simulato

Neuropsychological Predictors of Safety in Urban Left-Turn Scenarios

Left turns at urban intersections can be dangerous, especially when views are obstructed or pedestrians are present. Impairments in driver vision, motor, and cognition functions may further increase left-turn risk. We examined this problem in a simulated environment that included left-turn scenarios to study the driving behaviors of 28 drivers, ages 37 to 88 years, six of whom had “Useful Field of View” (UFOV) impairments. Subjects also completed a battery of neuropsychological tests. The simulated drive included an urban section with six left turns in three types of scenarios: 1) a semi truck blocking the view of oncoming traffic, 2) a lead vehicle obstruction, and 3) a pedestrian crossing ahead of the turning driver. Results showed a mean (SD) of 1.46 (1.60) collisions per driver (range 0 to 7), 83% of which occurred at intersections with semi trucks. Far visual acuity, contrast sensitivity, UFOV, Mini Mental State Examination, TrailMaking Test Part B, the Wisconsin Card Sort task, and age were all associated with the total number of collisions (Pearson correlation magnitudes between 0.37 to 0.77; p-values\u3c0.05). Spearman correlations were less significant. Findings indicate that visual obstruction by on oncoming semi-truck is a particularly dangerous left-turn situation

Transport of trace metals (Mn, Fe, Ni, Zn and Cd) in the western Arctic Ocean (Chukchi Sea and Canada Basin) in late summer 2012

Distributions of trace metals (Mn, Fe, Ni, Zn and Cd) in the western Arctic Ocean (Chukchi Sea and Canada Basin) in September 2012 were investigated to elucidate the mechanisms behind the transport of these metals from the Chukchi Shelf to the Canada Basin. Filtered (<0.22 μm) and unfiltered seawater samples were analyzed to determine dissolved (D) and total dissolvable (TD) trace metal concentrations, respectively. We identified maxima in vertical profiles for the concentrations of D-Fe and TD-Fe, as well as for the other four analyzed trace metals, which occurred in the halocline and/or near-bottom waters. Concentration profiles of all trace metals except for Cd also tended to show peaks near the surface, which suggest that the inflow of low-salinity Pacific-origin water from the Bering Strait, as well as local fresh water inputs such as river water and melting sea-ice, influenced trace metal concentrations. The distribution patterns and concentration ranges were generally similar between the D and TD fractions for Ni, Zn and Cd, which indicate that Ni, Zn and Cd were present mainly in their dissolved forms, whereas the concentrations of TD-Fe and TD-Mn were generally higher than those of D-Fe and D-Mn, respectively. These results are consistent with the results of previous studies of this region. For both Fe and Mn, labile particulate (LP) concentrations (the difference between the TD and D fractions, which is acid-leachable fraction in the particles during storage at pH 1.5?1.6) were highest in the near-bottom waters of the Chukchi Shelf region. The relationships between the distance from the shelf break and the concentrations of trace metals revealed that Fe and Mn concentrations in halocline waters tended to decrease logarithmically with distance, whereas changes in the concentrations of Ni, Zn, Cd and phosphate with distance were small. These results suggest that the distributions of Fe and Mn were controlled mainly by input from shelf sediment and removal through scavenging processes. Based on the phase distributions of Fe and Mn, which were calculated as ratios between the LP and D fractions, different behaviors between Fe and Mn were expressed during lateral transportation. The concentration of TD-Fe declined rapidly via removal of LP-Fe from the water column, whereas the concentration of TD-Mn declined more slowly through the transformation of D-Mn into LP-Mn. In contrast, the concentrations of D-Cd, D-Zn and D-Ni were more strongly correlated with phosphate levels, which suggest that, like phosphate, the distributions of Cd, Zn and Ni were generally controlled by the internal biogeochemical cycles of the ocean interior. Based on the findings of studies that have previously evaluated the concentration maxima of Ni, Zn and Cd within the halocline layer in the Canada Basin near the Canadian Arctic Archipelago, the elevated Ni, Zn and Cd concentrations in the halocline layer may extend across the Canada Basin from the Chukchi Sea shelf-break area. The determination coefficients for correlations with phosphate concentration varied between the concentrations of Ni, Zn and Cd, which suggest that the sources of these trace metals, such as sediments and sea-ice melting, affected their patterns of distributions differently. Our findings reveal the importance and impact of the halocline layer for the transport of trace metals in the western Arctic Ocean during the late summer. The existence of rich and various sources likely sustained the high concentrations of trace metals and their unique profiles in this region

Effects of Different Types of Cognitive Training on Cognitive Function, Brain Structure, and Driving Safety in Senior Daily Drivers: A Pilot Study

Background. Increasing proportion of the elderly in the driving population raises the importance of assuring their safety. We explored the effects of three different types of cognitive training on the cognitive function, brain structure, and driving safety of the elderly. Methods. Thirty-seven healthy elderly daily drivers were randomly assigned to one of three training groups: Group V trained in a vehicle with a newly developed onboard cognitive training program, Group P trained with a similar program but on a personal computer, and Group C trained to solve a crossword puzzle. Before and after the 8-week training period, they underwent neuropsychological tests, structural brain magnetic resonance imaging, and driving safety tests. Results. For cognitive function, only Group V showed significant improvements in processing speed and working memory. For driving safety, Group V showed significant improvements both in the driving aptitude test and in the on-road evaluations. Group P showed no significant improvements in either test, and Group C showed significant improvements in the driving aptitude but not in the on-road evaluations. Conclusion. The results support the effectiveness of the onboard training program in enhancing the elderly’s abilities to drive safely and the potential advantages of a multimodal training approach

The “Out-of-the-Loop” concept in automated driving: proposed definition, measures and implications

Despite an abundant use of the term “Out of the loop” (OOTL) in the context of automated driving and human factors research, there is currently a lack of consensus on its precise definition, how it can be measured, and the practical implications of being in or out of the loop during automated driving. The main objective of this paper is to consider the above issues, with the goal of achieving a shared understanding of the OOTL concept between academics and practitioners. To this end, the paper reviews existing definitions of OOTL and outlines a set of concepts, which, based on the human factors and driver behaviour literature, could serve as the basis for a commonly-agreed definition. Following a series of working group meetings between representatives from academia, research institutions and industrial partners across Europe, North America, and Japan, we suggest a precise definition of being in, out, and on the loop in the driving context. These definitions are linked directly to whether or not the driver is in physical control of the vehicle, and also the degree of situation monitoring required and afforded by the driver. A consideration of how this definition can be operationalized and measured in empirical studies is then provided, and the paper concludes with a short overview of the implications of this definition for the development of automated driving functions