Investigating the effectiveness of perceptual treatments on a crest vertical curve: A driving simulator study

Rural roads are characterized by a high percentage of run-off-the-road accidents and head-on collisions, mainly caused by inappropriate speeds and failure to maintain a proper lateral position along the roadway alignment. Among several road safety treatments, low-cost perceptual measures are considered an effective tool, as they generally increase the risk perceived by drivers, or even alter the drivers’ speed perception, and consequently tempting them to decrease their speeds. Their effectiveness has been widely recognized in a number of studies, especially with respect to road intersections and curves.The overall aim of this study is to investigate the effects of different perceptual treatments on driving speed, along a crest vertical curve of an existing two-lane rural road, in order to identify the most effective measure to reduce speed and define its subsequent implementation in the field. Three perceptual treatments were tested using a driving simulator: white peripheral transverse bars, red peripheral transverse bars and optical speed bars, with each one being painted along the approaching tangent to the crest vertical curve. The effects of these speed-reducing measures were investigated using a sample of forty-four participants, by comparing the driving speeds with those recorded under a baseline condition (without a treatment); these were also used to validate the driving simulator’s speed measurements with those found in the field. Moreover, subjective measures were collected, consisting of the driver’s static evaluation of the desired speed, risk perception and markings comprehension, based on screen shot pictures that represented the simulated configurations of the treatments.The findings demonstrated an overall effectiveness of the perceptual treatments, although only the red peripheral transverse bars were found to significantly reduce the driving speeds (−6 km/h). The analysis of the questionnaire yielded interesting information and demonstrated the importance of performing driving simulation tests for evaluating the effectiveness of perceptual treatments.Finally, the results confirmed the enormous potential of using driving simulators to pinpoint a number of speed-reducing measures, and consequently select the most effective one that reduces cost and promotes safety before its actual implementation in the field.     

Trust within Limits

Abstract

There have two recent challenges to the orthodoxy that ‘X trusts Y to ø’ is the fundamental notion of trust. Domenicucci and Holton maintain that trust, like love and friendship, is fundamentally two-place. Paul Faulkner argues to the more radical conclusion that the one-place ‘X is trusting’ is explanatorily basic. I argue that ‘X trusts Y in domain D’ is the explanatorily basic notion. I make the case that only by thinking of trust as domain-specific can we make sense of the relationships between trust and belief in goodwill, trust and distrust, and trust and trustworthiness. In addition, by modeling trust as essentially domain-specific we can account for the way in which wise trust in others is finely discriminating.     

The role of preference in speed choice

Individual differences with regard to speed preference may be a source of speed heterogeneity and conflicts in traffic, such as tailgating and dangerous overtaking. The main aim of the current study was to explore drivers’ speed preferences when driving for different reasons (saving money on fuel, driving safely, driving for fun or driving as usual) and the relationship of these preferences to observed speeds and self-reported speed. 193 drivers were interviewed at five different locations, and were asked about their speeds on roads they had just travelled. Drivers’ speeds on these roads were also sampled with a speed gun. The results showed large differences between speeds chosen for different driving purposes; the lowest speeds were chosen when the goal was economy and the highest when driving for fun. In addition, there were individual differences in speed preferences such that some drivers indicated that their usual speed was above what they believed was a safe speed while others indicated that they usually drove even slower than what they thought was safe. These differences may account for much of the speed heterogeneity observed in on-road behaviour. The results also showed that drivers’ speed choices are highly influenced by their usual speeds, even more so than their beliefs regarding what constitutes a safe speed, which may help explain non-compliance with speed limits. No relationship was found between speed choice and risk perception.     

Conditions under which children experience inhibitory difficulty with a "button-press" go/no-go task

Go/no-go tasks seem to provide a simple marker of inhibitory development in young children. Children are told to respond to one stimulus on go trials but to make no response to another stimulus on no-go trials; responding on no-go trials is assumed to reflect a failure to inhibit the go response. However, there is evidence to suggest that a type of go/no-go task, which we call the "button-press" task, does not require inhibition. We investigated the conditions under which young children (M=3 years 6 months, N=120) experience inhibitory difficulty with this type of task. The data suggest that the speed of stimulus presentation is crucial and that other studies using this type of task have presented the stimuli too briefly. The importance of establishing the inhibitory credentials of a task before it is used as a marker of inhibitory control is emphasized.     

Measuring the speed of recognising facially expressed emotions

Faces provide identity- and emotion-related information—basic cues for mastering social interactions. Traditional models of face recognition suggest that following a very first initial stage the processing streams for facial identity and expression depart. In the present study we extended our previous multivariate investigations of face identity processing abilities to the speed of recognising facially expressed emotions. Analyses are based on a sample of N=151 young adults. First, we established a measurement model with a higher order factor for the speed of recognising facially expressed emotions (SRE). This model has acceptable fit without specifying emotion-specific relations between indicators. Next, we assessed whether SRE can be reliably distinguished from the speed of recognising facial identity (SRI) and found latent factors for SRE and SRI to be perfectly correlated. In contrast, SRE and SRI were both only moderately related to a latent factor for the speed of recognising non-face stimuli (SRNF). We conclude that the processing of facial stimuli—and not the processing of facially expressed basic emotions—is the critical component of SRE. These findings are at variance with suggestions of separate routes for processing facial identity and emotional facial expressions and suggest much more communality between these streams as far as the aspect of processing speed is concerned.     

Prototypicality of responses of autistic,language disordered,and normal children in a word fluency task

This article describes an example of making pediatric neuropsychological assessments more time-efficient. Empirical support, including new data, for the utilization of an eight-subtest short form of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III; Wechsler, 1991) is reviewed. It is concluded that this short form of the WISC-III is a valid substitute for the complete version under most clinical circumstances, allowing the practitioner to expand on interview, history or more specific neuropsychological tests without adding financial or time burdens to the evaluation.     

Limits to preference and the sensitivity of choice to rate and amount of food

Studies of choice holding food‐amount ratio constant while varying food‐rate ratio within sessions showed that local changes in preference depend on relative amount of food. The present study investigated whether sensitivity of choice to food‐rate ratio and sensitivity to food‐amount ratio are independent of one another when food‐rate ratios are varied across sessions and food‐amount ratios are varied within sessions. Food deliveries for rats’ presses on the left and right levers were scheduled according to three different food‐rate ratios of 1:1, 9:1, and 1:9; each food‐rate ratio lasted for 106 sessions and was arranged independently of seven food‐amount ratios (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, and 1:7 food pellets) occurring within sessions in random sequence. Each amount ratio lasted for 10 food deliveries and was separated from another by a 60‐s blackout. Sensitivity to rate ratio was high (1.0) across food deliveries. Sensitivity to amount ratio was low when food rates were equal across alternatives, but was high when rate ratio and amount ratio opposed one another. When rate ratio and amount ratio went in the same direction, choice ratio reached an elevenfold limit which reduced sensitivity to approximately zero. We conclude that three factors affect sensitivity to amount: (1) the limit to preference, (2) the equal effect on preference of amounts greater than four pellets, and (3) the absence of differential effects of switches in amount in the equal‐rates (1:1) condition. Taken together, these findings indicate that rate and amount only sometimes combine independently as additive variables to determine preference when amount ratios vary frequently within sessions.     

Exploration of older drivers’ speeding behaviour

Speeding increases crash risk and resulting injury severity. Older drivers are at increased risk of injury due to frailty, at increased risk of crashing due to slower reaction times, and have less agility judging time and distance compared to younger drivers. However, there is little objective evidence about older drivers’ speeding behaviour. Cross-sectional data from older drivers living in the suburban outskirts of Sydney, Australia, were used to determine the proportion of drivers involved in speed events, and examine factors that may influence this behaviour. Driving speed was estimated in approximately one-second intervals using Global Positioning System (GPS) location. Speed events were defined as driving 1 km/h or more, with 3% tolerance, above a single speed limit, averaged over 30-s of travel. Driving data from one-week were recorded for 344 participants aged 75–94 years (median 80). The majority of participants (78%) were involved in a speed event. Speed events per participant ranged from zero to 186 (median 8). Younger participants, those living in rural areas, and those driving on familiar roads closer to home were more likely to be involved in speed events adjusted for distance driven. In addition, rural residents were more likely to be involved in speed events when they had not been a driver involved in a crash during the previous year compared to those involved in a crash. Measures of visual and cognitive function did not predict involvement with speed events per distance (p > 0.2). These findings are important for policy-makers and researchers addressing older drivers’ speeding to reduce the incidence of crashes and resulting fatalities and injuries. As no evidence was found for speeding being associated with functional decline, countermeasures to address speeding for other drivers seem likely to be relevant to older drivers.     

Speed-calming measures and their effect on driving speed – Test of a new technique measuring speeds based on GNSS data

Speeding increases the risk and severity of accidents, especially for vulnerable road users. Hence, minimisation of speeding in built-up areas is vital. Some countries widely use speed-calming measures (SCs). Documentation shows that SCs reduce speeding considerably although various types and designs of SCs affect this reduction. This paper includes studies of the effects from establishment of sinus speed humps of height 10 cm and length 950 cm and chicanes (with a free carriageway width of 5.30 cm and a length between the 0.5 m wide obstacles of 18 m) as a before/after study where the speed pattern after establishing SCs is compared with the one before. Floating Car Data used for analyses includes 3216 trips passing one/more SCs. The main results are that the effect from SCs decreases with the distance from the SCs and that a clear pattern is hard to establish above 75 m from the SC. Despite the apparent absence of more distant effects of each SC, there is an overall reduced average speed on the full length of a road with SCs. Humps reduce the mean speed comparable to the reduction from chicanes, but the speed variation is less reduced near chicanes, and especially prior to the arrival to such SC. Due to different traffic patterns around the two types of SCs, a direct comparison between the effects from humps and chicanes cannot be made. A tentative result at least for the two types of SCs studied is that the chicane results in a reduced effect on speed variation compared to the hump. The chicanes result in increased speed variation prior to the arrival to the SC compared to the humps. Hence, the indication is that chicanes might be less safe than humps due to speed variation although more research is needed especially concerning developing of best practice design for speed reducing devices and other speed-calming measures in built-up areas.     

On aggressiveness and violence in adolescence1

When considering aggressiveness and violence during adolescence, we must take into account multiple senses, which range from the healthy assertion of one's own space before others to the repetition of traumatic violent experiences such as the violation of bodily and spatial‐temporal boundaries. The author presents a survey of the views of different authors within psychoanalytical literature which allows us to question these terms, and turn then to the exploration of clinical practice. In studying the latter, acting out is brought to the fore, noting that not every adolescent act connotes a risk. The acts tackled in this case are those that, owing to their characteristics, may often endanger the very life of the adolescent. The author presents clinical material that focuses on adolescent acting out, highlighting the question of how to create, through the transference‐countertransference axis, a space within the analytic session where the patient's capacity to think may be incorporated, thus allowing the anticipation of action.