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.     

Psychometric and Piagetian intelligences: Toward resolution of controversy

Whether “psychometric” and “Piagetian” kinds of intelligence, as measured by instruments designed to measure these constructs, are the same or different is regarded as a question of whether they have the same or different courses of development with age. While factor analysis may not be fully adequate for investigation of this question, use of this technique with variables reflecting chronological age variation must involve elimination of the age effect in order to assess relations among the constructs measured. Humphreys and Parsons (1979) were justified in partialing out age in their reanalysis of a study by Stephens, McLaughlin, Miller, and Glass (1972), to show that the two constructs are highly correlated and possibly identical in the sample studied. Reanalyses of studies by DeVries and Kohlberg (1977) and by DeVries (1974) yield somewhat conflicting results on the identity between psychometric and Piagetian intelligences. The former study does not yield a convincing separation between them, whereas the latter suggests that they can be distinguished, though substantially correlated and both loaded with a general factor. Problems in further investigating the issue are discussed.     

The implications of low quality bicycle paths on gaze behavior of cyclists: A field test

Unlike for car driving and walking, the visual behavior during cycling is poorly documented. The aim of this experiment was to explore the visual behavior of adult bicycle users ‘in situ’ and to investigate to what extent the surface quality affects this behavior. Therefore cycling speed, gaze distribution and gaze location of five participants were analyzed on a high and a low quality bicycle track. Although there was no difference in cycling speed between the low and the high quality cycling path, there was an apparent shift of attention from distant environmental regions to more proximate road properties on the low quality track. These findings suggest that low quality bicycle tracks may affect the alertness and responsiveness of cyclists to environmental hazards.     

Aggressive driving: the contribution of the drivers and the situation

Aggressive driving is defined in terms of the frustration–aggression model. In that context aggressive driving is a syndrome of frustration-driven behaviors, enabled by the driver's environment. These behaviors can either take the form of instrumental aggression—that allows the frustrated driver to move ahead at the cost of infringing on other road users’ rights (e.g., by weaving and running red lights)—or hostile aggression which is directed at the object of frustration (e.g., cursing other drivers). While these behaviors may be reflective of individual differences in aggression, it is argued that the exclusive focus on the characteristics of the aggressive drivers and how to control them is short-sighted. Instead, this paper proposes a multi-factor approach to the problem. Five studies conducted so far tend to support this approach, by showing that specific aggressive behaviors—such as honking and running red lights—are associated with cultural norms, actual and perceived delays in travel, and congestion. Ergonomics-oriented approaches that involve environmental modifications are proposed.     

Serial learning: Identification of subjective subsequences

Learning of fixed arbitrary sequences proceeds by idiosyncratic subsequencing and assembly of the resulting subsequences. An error item that just precedes a subjective subsequence is a closely constrained member of that subsequence. Identification and characterization of subjective subsequences were accomplished by analyses of forward serial learning, free recall, and backward serial learning. We conclude that ordinary serial learning cannot be represented by traditional continuous-process theories, but instead must be treated by an organizational model.     

Retrieval of propositional information from long-term memory

Three experiments are reported in which subjects learn propositions like A hippie is in the park. The experiments manipulate the number of such propositions involving a particular person (e.g., hippie) or a particular location (e.g., park). After learning the material, subjects are asked to judge whether particular probe propositions are from the study set. Times to make these judgments about probe propositions increase with the number of study propositions involving the person or location used in the probe proposition. A model is presented which assumes a subject simultaneously accesses memory from all concepts in a probe proposition and serially searches through all study propositions involving each concept. Search of memory terminates as soon as one search process from a concept finds the probe proposition or exhausts the study propositions attached to that concept.     

Oral overcorrection: side effects and extended applications.

Experiment 1: In a specialized daycare program the use of oral overcorrection (contingent toothbrushing with an oral antiseptic) to suppress one child's thumbsucking at Language Time was found to suppress the behavior of another child who was not treated but who witnessed the target child's treatment. Experiment 2: The main effects of oral overcorrection were replicated. Contingent overcorrection threats (warnings), used independently, were then shown to suppress thumbsucking behavior that had returned to its baseline level. These effects were maintained one month after the threats were discontinued, but they did not generalize to other activity periods, particularly Nap Time. Experiment 3: Contingent threats were found to suppress the persistent nap-time thumbsucking of the child from Expt 2. Increments in certain other (nonoral) inappropriate behaviors were correlated with the suppression of thumbsucking. Threats to use oral overcorrection contingent upon nonoral misbehaviors at Nap Time were not effective. However, the actual use of oral overcorrection for these categories of nonoral misbehavior served to suppress these behaviors. Experimental controls combined treatment reversal and multiple baseline single-subject designs.     

Instigation of assertive behavior through videotape-mediated assertive models and directed practice

Twenty-eight undergraduate college women received an assertive training procedure in which they observed videotape-mediated assertive models and practiced nine types of assertive responses over a seven-week period. They reported significantly (p< 0.01) more assertive behavior and were rated as significantly (p< 0.01) more assertive than subjects receiving a placebo treatment and subjects receiving no treatment. There were also trends (p's = 0.17, 0.19, 0.29) for Ss receiving assertive training to report lower fear of social conflicts than subjects under the two control conditions.     

Reading the situation: The relationship between dyslexia and situational awareness for road sign information

Road signs are tools that provide crucial information to drivers about various roadway situations. Therefore, the present study aimed to assess the levels of ‘situation awareness’ held by drivers in relation to these signs. This study also assessed the relationship between dyslexia, road sign comprehension, and road sign situation awareness, thus building on the limited research in this area. Drivers completed measures of road sign comprehension and dyslexia. Drivers then completed three drives on a driving simulator; each followed by a probe containing queries about the perception, comprehension and projection of road signs seen in the preceding drive. Situation awareness was lowest at the level of projection. Further, dyslexia was negatively associated with road sign comprehension, and road sign situation awareness, suggesting that the disorder may be detrimental for multiple forms of road sign processing. Implications are provided in the form of a ‘SAFE’ driver training program that targets a holistic form of road sign processing which takes into account sign meanings in relation to both in-vehicle and outer-vehicle factors; thus encouraging proactive driver behaviour.     

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.