Traffic accident detection and anticipation is an obstinate road safety problem and painstaking efforts have been devoted. With the rapid growth of video data, Vision-based Traffic Accident Detection ...and Anticipation (named Vision-TAD and Vision-TAA) become the last one-mile problem for safe driving and surveillance safety. However, the long-tailed, unbalanced, highly dynamic, complex, and uncertain properties of traffic accidents form the Out-of-Distribution (OOD) feature for Vision-TAD and Vision-TAA. Current AI development may focus on these OOD but important problems. What has been done for Vision-TAD and Vision-TAA? What direction we should focus on in the future for this problem? A comprehensive survey is important. We present the first survey on Vision-TAD in the deep learning era and the first-ever survey for Vision-TAA. The pros and cons of each research prototype are discussed in detail during the investigation. In addition, we also provide a critical review of 31 publicly available benchmarks and related evaluation metrics. Through this survey, we want to spawn new insights and open possible trends for Vision-TAD and Vision-TAA tasks.
The impact and pileup mechanisms of unsteady granular flows impacting a rigid barrier are governed by the Froude conditions (Fr). Velocity and depth vary along the length of the flow. There is ...currently no widely accepted approach for characterizing Fr for impact and runup problems. In this study, a discrete element method (DEM) model was calibrated against a physical flume test. Eighty-six simulations were performed using the DEM model to investigate the equivalent Fr governing pileup height and impact pressure for unsteady single-surge dry granular flows against a rigid barrier. Fr and the grain diameter were varied. Results reveal that Fr within the frontmost 5% of a flow governs both pileup height and impact pressure. Thus, taking frontal velocity and maximum flow depth within the frontmost region is crucial for properly characterizing the runup height and impact load. Consistent characterization of Fr is possible near the longitudinal centre of a flow; the frontmost Fr can then be extrapolated from calibration curves. Results imply that existing studies that predict impact pressure based on nonfrontal Fr values may underestimate impact pressure by a factor of up to 2.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Connected and automated vehicles (CAVs) have the potential to improve safety by reducing and mitigating traffic accidents. They can also provide opportunities to reduce transportation energy ...consumption and emissions by improving traffic flow. Vehicle communication with traffic structures and traffic lights can allow individual vehicles to optimize their operation and account for unpredictable changes. This paper summarizes the developments and the research trends in coordination with the CAVs that have been reported in the literature to date. Remaining challenges and potential future research directions are also discussed.
Whether pregnancy is associated with severe injuries from motor vehicle crashes (MVCs) remains unclear. This study aimed to investigate the potential relationship between pregnancy and severity of ...injuries from MVCs.
We identified a total of 23,559 pregnant women victims who encountered MVCs during pregnancy as well as 94,236 age- and calendar year-at MVC matched non-pregnant women victims that are also involved in MVCs. Injury severity was assessed using the Maximum Abbreviated Injury Scale (MAIS) based on the diagnosis of medical claims after MVCs. Multinomial logistic regression models were used to estimate the odds ratio and corresponding 95 % CI of injury severity levels associated with pregnancy.
Pregnant women had a significantly higher risk of both severe (adjusted odds ratio, aOR = 1.79, 95 % CI = 1.54-2.08) and mild injuries (aOR = 8.63, 95 % CI = 8.21-9.07) following MVCs as compared to non-pregnant women victims. Particularly, pregnant women who were riding scooters had an increased risk of severe injury (aOR = 4.25, 95 % CI = 3.58-5.04). In addition, pregnant women who experienced MVC but without any injury were more likely to visit a clinic than non-pregnant MVC victims.
Pregnant women victims, particularly those who were riding scooters involved in MVCs suffered from a higher risk of severe injury as compared to their non-pregnant counterparts. Our findings suggest that women should consider avoiding riding a scooter and must use restrictive devices during pregnancy, which would help reduce the severity of injuries sustained following an MVC.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
BACKGROUND: Cannabis use results in impaired driving and an increased risk of motor vehicle crashes. Cannabinoid concentrations in blood and other matrices can remain high long after use, prohibiting ...the differentiation between acute and chronic exposure. Exhaled breath has been proposed as an alternative matrix in which concentrations may more closely correspond to the window of impairment; however, efficient capture and analytically sensitive detection methods are required for measurement. METHODS: Timed blood and breath samples were collected from 20 volunteers before and after controlled administration of smoked cannabis. Cannabinoid concentrations were measured using LC-MS/MS to determine release kinetics and correlation between the 2 matrices. RESULTS: DELTA.sup.9-Tetrahydrocannabinol (THC) was detected in exhaled breath for all individuals at baseline through 3 h after cannabis use. THC concentrations in breath were highest at the 15-min timepoint (median = 17.8 pg/L) and declined to <5% of this concentration in all participants 3 h after smoking. The decay curve kinetics observed for blood and breath were highly correlated within individuals and across the population. CONCLUSIONS: THC can be reliably detected throughout the presumed 3-h impairment window following controlled administration of smoked cannabis. The findings support breath THC concentrations as representing a physiological process and are correlated to blood concentrations, albeit with a shorter window of detection.
Cannabis effects on driving skills Hartman, Rebecca L; Huestis, Marilyn A
Clinical chemistry (Baltimore, Md.),
03/2013, Volume:
59, Issue:
3
Journal Article
Peer reviewed
Open access
Cannabis is the most prevalent illicit drug identified in impaired drivers. The effects of cannabis on driving continue to be debated, making prosecution and legislation difficult. Historically, ...delays in sample collection, evaluating the inactive Δ(9)-tetrahydrocannabinol (THC) metabolite 11-nor-9-carboxy-THC, and polydrug use have complicated epidemiologic evaluations of driver impairment after cannabis use.
We review and evaluate the current literature on cannabis' effects on driving, highlighting the epidemiologic and experimental data. Epidemiologic data show that the risk of involvement in a motor vehicle accident (MVA) increases approximately 2-fold after cannabis smoking. The adjusted risk of driver culpability also increases substantially, particularly with increased blood THC concentrations. Studies that have used urine as the biological matrix have not shown an association between cannabis and crash risk. Experimental data show that drivers attempt to compensate by driving more slowly after smoking cannabis, but control deteriorates with increasing task complexity. Cannabis smoking increases lane weaving and impaired cognitive function. Critical-tracking tests, reaction times, divided-attention tasks, and lane-position variability all show cannabis-induced impairment. Despite purported tolerance in frequent smokers, complex tasks still show impairment. Combining cannabis with alcohol enhances impairment, especially lane weaving.
Differences in study designs frequently account for inconsistencies in results between studies. Participant-selection bias and confounding factors attenuate ostensible cannabis effects, but the association with MVA often retains significance. Evidence suggests recent smoking and/or blood THC concentrations 2-5 ng/mL are associated with substantial driving impairment, particularly in occasional smokers. Future cannabis-and-driving research should emphasize challenging tasks, such as divided attention, and include occasional and chronic daily cannabis smokers.
This article analyses the impact that the confinement measures or quarantine imposed in Spain on 15 March 2020 had on urban mobility in the northern city of Santander. Data have been collected from ...traffic counters, public transport ITS, and recordings from traffic control cameras and environmental sensors to make comparisons between journey flows and times before and during the confinement. This data has been used to re-estimate Origin-Destination trip matrices to obtain an initial diagnostic of how daily mobility has been reduced and how the modal distribution and journey purposes have changed. The impact on externalities such as NO2 emissions and traffic accidents have also been quantified. The analysis revealed an overall mobility fall of 76%, being less important in the case of the private car. Public transport users dropped by up to 93%, NO2 emissions were reduced by up to 60%, and traffic accidents were reduced by up to 67% in relative terms.
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