Speed behaviour as a choice between observing and exceeding the speed limit

Despite speed behaviour being defined as a choice between several possible speeds, studies using theory of reasoned action or theory of planned behaviour to predict and understand speed behaviour have focused on exceeding and not on observing the speed limit. This study examines whether the evaluation of exceeding but also of observing the speed limit contributes to improving predictions of self-reported speed behaviour and determining intentions to produce each of these two behavioural options. For a specific driving situation (straight road with 90 km/h speed limit), 238 young male drivers reported the speed at which they would drive at and where asked to assess the theory of planned behaviour key constructs with respect to observing and exceeding the speed limit by at least 20 km/h. Results showed that the amount of explained variance of self-reported speed behaviour, as well as intentions to observe and to exceed the speed limit by at least 20 km/h, increased significantly when the evaluations of the two options were introduced in the same stepwise regression analysis. Theoretical and practical implications of the results are discussed.     

Taking Law Seriously: Starting Points of the Hart/Devlin Debate*

The famous mid-20th century debate between Patrick Devlin and Herbert Hart about the relationship between law and morality addressed the limits of the criminal law in the context of a proposal by the Wolfenden Committee to decriminalize male homosexual activity in private. The original exchanges and subsequent contributions to the debate have been significantly constrained by the terms in which the debate was framed: a focus on criminal law in general and sexual offences in particular; a preoccupation with the so-called “harm principle,” a sharp delineation of the realms of law and morality, and a static conception of the relationship between them. This article explores the limitations imposed by these various starting-points and argues for a holistic and symbiotic understanding of the relationship between law and morality. * Thanks to Tony Connolly, Leighton McDonald and Niki Lacey for penetrating and suggestive comments on previous versions.     

Task specificity and the timing of discrete aiming movements

In discrete aiming movements the task criteria of time-minimization to a spatial target (e.g., Fitts, 1954) and time-matching to a spatial-temporal goal (e.g., Schmidt et al., 1979) tend to produce different functions of the speed-accuracy trade-off. Here we examined whether the task-related movement speed-accuracy characteristics were due to differential space-time trade-offs in time-matching, velocity-matching and time-minimizing task goals. Twenty participants performed 100 aiming trials for each of 15 combinations of task-type (3) and space-time condition (5). The prevalence of the primary types of sub-movement (none, pre-peak, post-peak, undershooting and overshooting) was determined from the kinematics of the movement trajectory. There were comparable distributions of trajectory sub-movement profiles and space-time movement outcomes across the three tasks at the short movement duration that became increasingly dissimilar over decreasing movement velocity and increasing movement time conditions. Movement time was the most influential variable in mediating sub-movement characteristics and the spatial/temporal outcome accuracy and variability of discrete aiming tasks – a role that was magnified in the explicit task demands of time-matching. The time-matching and time-minimization task goals in discrete aiming induce qualitatively different control processes that progressively contribute beyond the minimal time conditions to task-specific space-time accuracy and variability characteristics of the respective movement speed-accuracy functions.     

The Limits of Medical Practice

Theoretical Medicine and Bioethics - Should medicine be defined as the enterprise in charge of the health problems of society? If so, then any problem (individual, public, social or political) that...     

速度与认知成绩及年龄关系的研究

应用累加成绩－反应时曲线比较研究了青年组与老年组五项作业速度与成绩之间的关系,这五项作业是数字旋转,心算、符号数字、汉字数字和图形空间定位,结果表明：（１）老年组五项作业的累加成绩－－反应时曲线均较青年组上升缓慢,表明老年组需要较长的反应时,便可获得与青年人相当的累加是分;（２）老年组累加成绩－反应时曲线上升的快慢还与作业的性质及难度有一定。上述结果表明,在所研究作业的难度范围内,速度减慢是老年人     

A Dogma of Naturalism

One of the major historical effects of Quine's attacks upon the analytic‐ synthetic distinction has been to popularise the belief that philosophy is continuous with science. Currently, most philosophers believe that such continuity is an inevitable consequence of naturalism. This article argues that though Quine's semantic holism does imply that there is no sharp distinction between truths discoverable by scientific investigation and truths discoverable by philosophical investigation, it also implies that there is a perfectly sharp and natural distinction between natural science and naturalistic philosophy.     

Can fast and slow intelligence be differentiated?

Responses to items from an intelligence test may be fast or slow. The research issue dealt with in this paper is whether the intelligence involved in fast correct responses differs in nature from the intelligence involved in slow correct responses. There are two questions related to this issue: 1. Are the processes involved different? 2. Are the abilities involved different? An answer to these questions is provided making use of data from a Raven-like matrices test and a verbal analogies test, and the use of a psychometric branching model. The branching model is based on three latent traits: speed, fast accuracy and slow accuracy, and item parameters corresponding to each of these. The pattern of item difficulties is used to draw conclusions on the cognitive processes involved. The results are as follows: 1. The processes involved in fast and slow responses can be differentiated, as can be derived from qualitative differences in the patterns of item difficulty, and fast responses lead to a larger differentiation between items than slow responses do. 2. The abilities underlying fast and slow responses can also be differentiated, and fast responses allow for a better differentiation between the respondents.     

The effect of widening longitudinal road markings on driving speed perception

Road markings may influence driver behavior, and therefore road safety. An increase in the width of road markings might lead drivers to perceive lanes to be narrower than they really are, creating the illusion of traveling faster. The objective of this paper is to analyze whether wider longitudinal road markings can affect the perception of lane width and thus induce drivers to slow down. To this end, three curves with reduced visibility were selected for a field experiment. The road markings were painted wider than normal, and video recordings were made with narrow and wide markings by a camera installed in a vehicle. A total of 14 videos were shown to each of the 185 participants; then a survey was carried out to analyze in which video the participants perceived higher speed. The results showed that if the participants perceived differences in speed, the higher speed was perceived with the wide markings. This perception of higher speed increased if the participant was female, or if the participant had ever had an accident. In view of the obtained results, it can be said that the use of wider road markings could help reduce vehicle speed, thus contributing to improved road safety.     

Examining U.S. drivers’ characteristics in relation to how frequently they engage in speeding on freeways

Speeding and speed-related crashes have consistently represented over 25% of all traffic fatalities over the past two decades. The severity of these speed-related incidents not only impact the drivers but all road users. Thus, characterizing drivers who speed, understanding their motivations, and identifying the types of risky driving behaviors associated with speeding play a critical role in developing, implementing, and sustaining effective countermeasures. Using a survey administered to a U.S. nationally representative sample (N = 2,930 licensed drivers aged 16 or older), this study develops a partial proportional odds model to examine differences in characteristics between types of speeders – frequent, occasional, and non-speeders – and explores characteristics and risk driving behaviors that are most associated with speeding behavior. Additionally, motivations for speeding are examined for drivers who frequently speed compared with those who occasionally speed. Results show speeders tended to engage in other unsafe driving behaviors, such as distracted, aggressive, unbelted, and alcohol-impaired driving. Among demographic and socio-economic variables examined in this study, drivers’ age was the greatest associated determinant. The association with engagement in red-light running, however, outweighed that with drivers’ age. Interestingly, the interaction between educational attainment and engagement in aggressive driving was also predictive of speeding behavior. For motivations for speeding, frequent speeders were more likely to report enjoying driving fast and disagreeing with speed limits compared with occasional speeders. The findings of this study are useful towards identifying the various characteristics and behaviors of drivers who engage in speeding, which can provide future insights into where effective countermeasures and prevention efforts should be focused.