Driving context influences drivers\u27 decision to engage in visual-manual phone tasks: evidence from a naturalistic driving study

Visual-manual phone tasks (i.e., texting, dialing, reading) are associated with anincreased crash risk. This study investigated how the driving context influences drivers\u27 decisions toengage in visual-manual phone tasks in naturalistic driving. Method: Video-recordings of 1432 car tripswere viewed to identify visual-manual phone tasks and passenger presence. Video, vehicle signals, andmap data were used to classify driving context (i.e., curvature, other vehicles) before and during thephone tasks (N=374). Vehicle signals (i.e., speed, yaw rate, forward radar) were available for alldriving. Results: The drivers were more likely to engage in phone tasks while standing still, and lesslikely while driving at high speeds or executing sharp turns, or when a passenger was present. Leadvehicle presence did not influence how likely drivers were to engage, but they adjusted their tasktiming to situations when the lead vehicle was increasing speed, resulting in increasing time headway.The drivers adjusted task timing until after making sharp turns and lane change maneuvers. Incontrast to previous driving simulator studies, there was no evidence of drivers reducing speed as aconsequence of phone task engagement. Conclusions: The results show that experienced drivers areskilled at using information about current and upcoming driving context to decide when to safelyengage in visual-manual phone tasks. However, drivers may fail to sufficiently increase safety marginsto allow time to respond to possible unpredictable events (e.g., lead vehicle braking). PracticalApplications: Advanced driver assistance systems should facilitate and possibly boost drivers\u27 selfregulatingbehavior. For instance, they might recognize when appropriate adaptive behavior is missingand advice or alert accordingly. The results from this study could also inspire training programs fornovice drivers, or locally classify roads in terms of the risk associated with secondary task engagementwhile driving

It’s about time! Earlier take-over requests in automated driving enable safer responses to conflicts

Automated driving (AD), which takes full responsibility for the driving task in certain conditions, is currently being developed. An important concern in AD is how to design a take-over request (TOR) that mitigates automation effects (e.g., delayed responses to conflict scenarios) that previous literature from simulator experiments has shown can occur. To address this concern, this study aims to investigate and compare driver responses to TORs and a lead-vehicle cut-out scenario under three conditions: (1) after a period of AD with a TOR issued early (18 s time-to-collision), (2) same as (1) except with a TOR issued late (9 s time-to-collision), and (3) baseline, with adaptive cruise control (ACC). This paper also compares the results to those of a previous study using the same conflict scenario but with near-perfect assisted driving system (SAE Level 2). The lead-vehicle cut-out scenario was encountered on a test track after 30 minutes driving with either ACC or AD. In AD the TOR was issued prior to the conflict object was revealed to the participants when the lead vehicle performed the cut-out (at conflict onset). This TOR strategy differed from previous driving-simulator studies that issued the TOR at conflict onset. The participants had to respond by steering and/or braking to avoid a crash. Our findings show that, independent of TOR timing, the drivers required similar amounts of time to 1) direct their first glance to the human–machine interface, 2) look forward, 3) end their secondary task, 4) put their hands on the steering wheel, and 5) deactivate automation. However, when the TOR was issued early rather than late, they started to brake earlier (even before conflict onset). All participants successfully managed to avoid crashing with the object, independent of the condition. AD with an early TOR resulted in the earliest response, while ACC drivers responded slightly earlier than the drivers in AD with the late TOR. Our findings do not support the findings of severe automation effects in previous driving-simulator studies. One reason for the difference is that when a TOR is issued prior to conflict onset, drivers are given the time needed for their preparatory actions (e.g., placing hands on the wheel, deactivating AD) that is not needed when driving with ACC or in manual driving (baseline), before having to respond to the conflict scenario. Thus, at conflict onset the drivers in AD are as ready to act (hands on wheel, eyes forward) as the drivers in the baseline and can perform an avoidance manoeuvre similar as to the baseline drive. Overall, the present study shows that AD does not need to end up in a highly critical situation if the TOR is issued early enough. In fact, AD with an early TOR may be safer than driving with ACC, because in the former drivers are more likely to brake earlier in preparation for the conflict. Finally, a TOR clearly communicates the need for drivers to resume manual control and handle potential events when AD has been deactivated. In our study, once the drivers had taken control, they clearly understood their responsibilities to respond to the conflict, in contrast to a previous study with a similar, near-perfect assisted driving system

Driver Visual Attention Before and After Take-Over Requests During Automated Driving on Public Roads

ObjectiveThis study aims to understand drivers’ visual attention before and after take-over requests during automated driving (AD), when the vehicle is fully responsible for the driving task on public roads.BackgroundExisting research on transitions of control from AD to manual driving has mainly focused on take-over times. Despite its relevance for vehicle safety, drivers’ visual attention has received little consideration.MethodThirty participants took part in a Wizard of Oz study on public roads. Drivers’ visual attention was analyzed before and after four take-over requests. Visual attention during manual driving was also recorded to serve as a baseline for comparison.ResultsDuring AD, the participants showed reduced visual attention to the forward road and increased duration of single off-road glances compared to manual driving. In response to take-over requests, the participants looked away from the forward road toward the instrument cluster. Levels of visual attention towards the forward road did not return to the levels observed during manual driving until after 15\ua0s had passed.ConclusionDuring AD, drivers may look toward non-driving related task items (e.g., mobile phone) instead of forward. Further, when a transition of control is required, drivers may take over control before they are aware of the driving environment or potential threat(s). Thus, it cannot be assumed that drivers are ready to respond to events shortly after the take-over request.ApplicationIt is important to consider the effect of the design of take-over requests on drivers’ visual attention alongside take-over times

Driver conflict response during supervised automation: Do hands on wheel matter?

Securing appropriate driver responses to conflicts is essential in automation that is not perfect (because the driver is needed as a fall-back for system limitations and failures). However, this is recognized as a major challenge in the human factors literature. Moreover, in-depth knowledge is lacking regarding mechanisms affecting the driver response process. The first aim of this study was to investigate how driver conflict response while using highly reliable (but not perfect) supervised automation differ for drivers that (a) crash or avoid a conflict object and (b) report high trust or low trust in automation to avoid the conflict object. The second aim was to understand the influence on the driver conflict response of two specific factors: a hands-on-wheel requirement (with vs. without), and the conflict object type (garbage bag vs. stationary vehicle). Seventy-six participants drove with highly reliable but supervised automation for 30 minutes on a test track. Thereafter they needed to avoid a static object that was revealed by a lead-vehicle cut-out. The driver conflict response was assessed through the response process: timepoints for driver surprise reaction, hands-on-wheel, driver steering, and driver braking. Crashers generally responded later in all actions of the response process compared to non-crashers. In fact, some crashers collided with the conflict object without even putting their hands on the wheel. Driver conflict response was independent of the hands-on-wheel requirement. High-trust drivers generally responded later than the low-trust drivers or not at all, and only high trust drivers crashed. The larger stationary vehicle triggered an earlier surprise reaction compared to the garbage bag, while hands-on-wheel and steering response were similar for the two conflict object types. To conclude, crashing is associated with a delay in all actions of the response process. In addition, driver conflict response does not change with a hands-on-wheel requirement but changes with trust-level and conflict object type. Simply holding the hands on the wheel is not sufficient to prevent collisions or elicit earlier responses. High trust in automation is associated with late response and crashing, whereas low trust is associated with appropriate driver response

Automation aftereffects: the influence of automation duration, test track and timings

Automation aftereffects (i.e., degraded manual driving performance, delayed responses, and more aggressive avoidance maneuvers) have been found in driving simulator studies. In addition, longer automation duration seems to result in more severe aftereffects, compared to shorter duration. The extent to which these findings generalize to real-world driving is currently unknown. The present study investigated how automation duration affects drivers\u27 take-over response quality and driving performance in a road-work zone. Seventeen participants followed a lead vehicle on test track. They encountered the road-work zone four times: two times while driving manually, and after a short and a long automation duration. The take-over request was issued before the lead vehicle changed lane to reveal the road-work zone. After both short and long automation durations, all drivers deactivated automation well ahead of the road-work zone. Compared to manual, drivers started their steering maneuvers earlier or at similar times after automation (independently of duration), and none of the drivers crashed. However, slight increases in vehicle speed and accelerations were observed after exposure to automation. In sum, the present study did not observe as large automation aftereffects on the test track as previously found in driving simulator studies. The extent to which these results are a consequence of a more realistic test environment, or due to the duration between the timings for the take-over request and the conflict appearance, is still unknown

Driver response to take-over requests in real traffic

Existing research on control-transitions from automateddriving (AD) to manual driving mainly stems from studiesin virtual settings. There is a need for studies conducted in realsettings to better understand the impacts of increasing vehicleautomation on traffic safety. This study aims specifically to understandhow drivers respond to take-over requests (TORs) in realtraffic by investigating the associations between 1) where driverslook when receiving the TOR, 2) repeated exposure to TORs, and3) the drivers’ response process. In total, thirty participants wereexposed to four TORs after about 5–6 min of driving with AD onpublic roads. While in AD, participants could choose to engage innon-driving-related tasks (NDRTs).When they received the TOR,for 38% of TORs, participants were already looking on path. Forthose TORs where drivers looked off path at the time of the TOR,the off-path glance was most commonly towards an NDRT item.Then, for 72% of TORs (independent on gaze direction), driversstarted their response process to the TOR by looking towardsthe instrument cluster before placing their hands on the steeringwheel and their foot on the accelerator pedal, and deactivatingautomation. Both timing and order of these actions varied amongparticipants, but all participants deactivated AD within 10 s fromthe TOR. The drivers’ gaze direction at the TOR had a strongerassociation with the response process than the repeated exposureto TORs did. Drivers can respond to TORs in real traffic. However,the response should be considered as a sequence of actions thatrequires a certain amount of time

Cardiovascular risk with androgen deprivation therapy for prostate cancer: Potential mechanisms.

Androgen deprivation therapy (ADT) is frequently used for the treatment of advanced prostate cancer. ADT is associated with numerous side effects related to its mode of action, namely the suppression of testosterone to castrate levels. Recently, several large retrospective studies have also reported an increased risk of diabetes and cardiovascular disease in men receiving ADT, although these risks have not been confirmed by prospective randomized trials. We review the literature to consider the risk of cardiovascular disease with different forms of ADT and examine in detail potential mechanisms by which any such risk could be mediated. Mechanisms discussed include the metabolic syndrome resulting from low testosterone level and the potential roles of testosterone flare, gonadotropin-releasing hormone receptors outside the pituitary gland, and altered levels of follicle-stimulating hormone. Finally, the clinical implications for men prescribed ADT for the treatment of advanced prostate cancer are considered

Élelmiszerek és takarmányok D-aminosav tartalma II. : az aminosav enantiomerek szétválasztása és meghatározása OPA/TATG származékképzés után

A kidolgozott módszer alkalmazható az α-aminosav enantiomerek szétválasztására és meghatározására az o-ftálaldehiddel (OPA) és az optikailag aktív 2,3,4,6-tetra-Oacetil-1-tio-β-glükopiranoziddal történô származékképzés után fordított fázisú folyadékkromatográfiával. A származékképzés során a reakció szobahômérsékleten néhány perc alatt lejátszódik, és a kapott származékok igen stabilak. A képzett diasztereomerek szelektivitása - a lizin és az ornitin kivételével - különösen jónak mondható. A származékok fluoreszcenciás gerjesztési és emissziós maximuma 342 és 410 nm volt. A kimutathatóság határa fluoreszcens detektor esetén 2 pmol, elektrokémiai detektor esetén pedig 1 pmol volt az aminosavak többségére. A leirt módszerrel meghatározták a ribonukleáz gáz- és folyadékfázisú hidrolízise során fellépô racemizáció nagyságát is. A method is described for the separation and determination of α-amino acid derivatization with o-phtalaldehyde (OPA) and optically active 2,3,4,6-tetra-O-acetyl-1- thio-β-glucopyranoside by reverse phase liquid chromatography. It can be stated that the selectivity of the diastereomers formed - with the exception of lysine and ornithine - is especially good. The fluorescence excitation and emission maxima of the derivatives were 342 and 410 nm, respectively. The detection limit for the majority of amino acids was 2 pmol in case of fluorescence detector and 1 pmol using electrochemical detector. The extent of racemization occurring during gas and liquid phase hydrolysis of ribonuclease was determined by the method described. Die ausgearbeitete Methode ist für die Trennung und Bestimmung von αAminosäure-Enantiomeren nach Derivatbildung mit o-Phtalaldehyd (OPA) und mit dem optisch aktiven 2,3,4,6-Tetra-O-Acetyl-1-Thio-β-Glycopiranosid unter Anwendung der Umkehrphasenflüssigkeitschromatographie geeignet. Die Reaktion läuft während der Derivatenbildung bei Zimmertemperatur in einigen Minuten ab und die erhaltenen Derivate sind recht stabil. Die Selektivität der gebildeten Diastereomere kann mit Ausnahme von Lysin und Ornithin als besonders günstig eingeschätzt werden. Die Fluoreszenzinduktions-und Emissionsmaxima betrugen 342 und 410 nm. Die Nachweisgrenze liegt für die Mehrheit der Aminosäuren im Falle des Fluoreszenzdetektors bei 2 pmol und des elektrochemischen Detektors bei 1 pmol. Mit der beschriebenen Methode wurde auch die größe der Razemisation bei der Hydrolyse der Ribonuclease in der Gas-und Flüssigkeitsphase bestimmt

Low Serum Levels of Dehydroepiandrosterone Sulfate Predict All-Cause and Cardiovascular Mortality in Elderly Swedish Men.

Context: The age-related decline in dehydroepiandrosterone (DHEA) levels is thought to be of importance for general and vascular aging. However, data on the association between DHEA and mortality are conflicting. Objectives: We tested the hypothesis that low serum DHEA and DHEA sulfate (DHEA-S) levels predict all-cause and cardiovascular disease (CVD) death in elderly men. Design, Setting, and Participants: We used gas/liquid chromatography-mass spectrometry to analyze baseline levels of DHEA and DHEA-S in the prospective population-based MrOS Sweden study (2644 men, aged 69-81 yr). Mortality data were obtained from central registers and analyzed using Cox proportional hazards regressions. Main Outcome Measures: All-cause and CVD mortality by serum DHEA(-S) levels. Results: During a mean 4.5-yr follow-up, 328 deaths occurred. Low levels of DHEA-S (quartile 1 vs. quartiles 2-4), predicted death from all causes [hazard ratio (HR) 1.54, 95% confidence interval (CI) 1.21-1.96; adjusted for traditional cardiovascular risk factors], from CVD (n = 123 deaths; HR 1.61, 95% CI 1.10-2.37) and ischemic heart disease (n = 73; HR 1.67, 95% CI 1.02-2.74) but not cancer. Analyses with DHEA gave similar results. The association between low DHEA-S and CVD death remained after adjustment for C-reactive protein and circulating estradiol and testosterone levels. When stratified by the median age of 75.4 yr, the mortality prediction by low DHEA-S was more pronounced among younger (age adjusted HR for CVD death 2.64, 95% CI 1.37-5.09) than older men (HR 1.30, 95% CI 0.83-2.04). Conclusions: Low serum levels of DHEA(-S) predict death from all causes, CVD, and ischemic heart disease in older men