Cycling Skill Inventory: Assessment of motor-tactical skills and safety motives.

Objective: It is well established within the traffic psychology literature that a distinction can be made between driving skill and driving style. The majority of self-report questionnaires have been developed for car drivers, whereas only limited knowledge exists on the riding skill and style of cyclists. Individual differences in cycling skills need to be understood in order to apply targeted interventions.Methods: This study reports on a psychometric analysis of the Cycling Skill Inventory (CSI), a self-report questionnaire that asks cyclists to rate themselves from definitely weak to definitely strong on 17 items. Herein, we administered the CSI using an online crowdsourcing method, complemented with respondents who answered the questionnaire using paper and pencil (n = 1,138 in total). Our analysis focuses on understanding the major sources of variance of the CSI and its correlates with gender, age, exposure, and self-reported accident involvement as a cyclist.Results: The results showed that 2 components underlie the item data: Motor-tactical skills and safety motives. Correlational analyses indicated that participants with a higher safety motives score were involved in fewer self-reported cycling accidents in the past 3 years. The analysis also confirmed well-established gender differences, with male cyclists having lower safety motives but higher motor-tactical skills than female cyclists.Conclusions: The nomological network of the CSI for cyclists is similar to that of the Driving Skill Inventory for car drivers. Safety motives are a predictor of self-reported accident involvement among cyclists.

Cyclists' eye movements and crossing judgments at uncontrolled intersections: An eye-tracking study using animated video clips.

Research indicates that crashes between a cyclist and a car often occur even when the cyclist must have seen the approaching car, suggesting the importance of hazard anticipation skills. This study aimed to analyze cyclists' eye movements and crossing judgments while approaching an intersection at different speeds. Thirty-six participants watched animated video clips with a car approaching an uncontrolled four-way intersection and continuously indicated whether they would cross the intersection first. We varied (1) car approach scenario (passing, colliding, stopping), (2) traffic complexity (one or two approaching cars), and (3) cyclist's approach speed (15, 25, or 35 km/h). Results showed that participants looked at the approaching car when it was relevant to the task of crossing the intersection and posed an imminent hazard, and they directed less attention to the car after it had stopped or passed the intersection. Traffic complexity resulted in divided attention between the two cars, but participants retained most visual attention to the car that came from the right and had right of way. Effects of cycling speed on cyclists' gaze behavior and crossing judgments were small to moderate. In conclusion, cyclists' visual focus and crossing judgments are governed by situational factors (i.e., objects with priority and future collision potential), whereas cycling speed does not have substantial effects on eye movements and crossing judgments.

Concurrent audio-visual feedback for supporting drivers at intersections: A study using two linked driving simulators.

A large portion of road traffic crashes occur at intersections for the reason that drivers lack necessary visual information. This research examined the effects of an audio-visual display that provides real-time sonification and visualization of the speed and direction of another car approaching the crossroads on an intersecting road. The location of red blinking lights (left vs. right on the speedometer) and the lateral input direction of beeps (left vs. right ear in headphones) corresponded to the direction from where the other car approached, and the blink and beep rates were a function of the approaching car's speed. Two driving simulators were linked so that the participant and the experimenter drove in the same virtual world. Participants (N = 25) completed four sessions (two with the audio-visual display on, two with the audio-visual display off), each session consisting of 22 intersections at which the experimenter approached from the left or right and either maintained speed or slowed down. Compared to driving with the display off, the audio-visual display resulted in enhanced traffic efficiency (i.e., greater mean speed, less coasting) while not compromising safety (i.e., the time gap between the two vehicles was equivalent). A post-experiment questionnaire showed that the beeps were regarded as more useful than the lights. It is argued that the audio-visual display is a promising means of supporting drivers until fully automated driving is technically feasible.

Do young novice drivers overestimate their driving skills more than experienced drivers? Different methods lead to different conclusions.

In this study we argue that drivers have to make an assessment of their own driving skills, in order to sufficiently adapt to their task demands in traffic. There are indications that drivers in general, but novice drivers in particular, overestimate their driving skills. However, study results differ on the subject of self-assessment of skills. The objectives of this paper are (1) to study whether novice drivers indeed overestimate their driving skills more than experienced drivers; and (2) to evaluate the influence of the method to measure self-assessment of skills (i.e. comparison to 'average' and 'peer' driver versus independent measures of own performance). The results show that the conclusion of whether novice drivers overestimate their driving skills is highly affected by the method chosen to measure self-assessment of skills. When drivers are asked to compare themselves to the average and peer driver, we can conclude that novice drivers are not as optimistic about their driving skills as has been reported in the past. They seem to recognize that they are not as skilled (yet) as the average driver. However, when comparing their self-assessment with their actual behaviour there are indications that they overestimate their driving skills.

Effects of incentive programs to stimulate safety belt use: a meta-analysis.

The effects of campaigns using tangible incentives (rewards) to promote safety belt usage have been evaluated by means of a meta-analytic approach. Two coders extracted a total number of 136 short-term and 114 long-term effect sizes and coded many other variables from 34 journal articles and research reports. The results show a mean short-term increase in use rates of 20.6 percentage points; the mean long-term effect was 13.7 percentage points. Large scale studies report smaller effect sizes than small scale studies; when studies were weighted by the (estimated) number of observations, the weighted mean effect sizes were 12.0 and 9.6 percentage points for the short and long term, respectively. The main factors that influence the magnitude of the reported short-term effect of the programs were the initial baseline rate (which was highly correlated with the presence or absence of a safety belt usage law), the type of population involved, whether incentives were delivered immediately or delayed, and whether incentives were based on group or individual behaviour. Together these four variables accounted for 64% of the variance. Other variables, such as the duration of the intervention, the probability of receiving a reward, and the value of the reward were not related to the short-term effect sizes. The relationship between moderating variables and long-term effects was less clear.

Enforcement or incentives? Promoting safety belt use among military personnel in the Netherlands.

During a nationwide campaign to promote safety belt use among military personnel, a field study was conducted at 12 different military bases in the Netherlands. Amount of enforcement, type of publicity, and incentive strategies were varied among military bases. Observations of safety belt use among servicemen in their personal vehicles were conducted before the campaign, immediately following the campaign, and 3 months later. Safety belt use increased from 65% during baseline to 73% directly after the campaign and to 76% 3 months later. An overall 28.6% increase in safety belt use (from 63% to 81%) was observed at seven bases, whereas no changes were found at five bases (68% on all occasions). To a large degree the effects were due to a 37.7% increase among young drivers. These results confirmed that enforcement, as well as incentives, can be effective in promoting safety belt use. However, treatment effects were not systematic, thereby complicating the interpretation of the results. Implications of these varied outcomes are discussed.

Time courses in visual-information processing: some empirical evidence for inhibition.

In the literature two different views on the time course of activation of "recognition units"--hypothetical units that represent identity information--are proposed. The first view assumes that the recognition units accumulate activation gradually over time. The second assumes that the activation levels increase fast initially and then start to decrease. Hagenzieker and Van der Heijden (1990) have proposed a more general information-processing model, which is compatible with both views. In this model a threshold determines what type of time course will be obtained. For below-threshold-activation values a gradual accumulation of activation will be found; for above-threshold values activation levels will first increase and then, because of inhibition, decrease. This model served as a starting-point for the present paper. Elaboration of this model led to two testable hypotheses with regard to identification performance. The first prediction is that evidence for inhibition should be observed only under relatively bright luminance conditions. The second is that, given inhibition, the amount of the effect of this inhibition should increase over time. A partial-report bar-probe task was used to test the predictions. The experiment involved two luminance conditions and the information was sampled at two different moments in time. To control for possible localization artefacts a digit-naming task was also used. Evidence for inhibition was found in both luminance conditions. In accordance with the model the amount of the effect of inhibition increased over time.

Time courses in visual-information processing: some theoretical considerations.

In the literature two different views with regard to the time course of activation of "recognition units"--hypothetical entities that represent identity information--are proposed. Both views are derived from a restricted set of phenomena in visual perception. The first view gets its intuitions from phenomena such as those summarized by Bloch's law; these phenomena show integration or summation of activation over time. This "grow-and-grow" view assumes that recognition units accumulate activation gradually over time. The second view finds its inspiration in phenomena such as Mach-bands and simultaneous contrast; these phenomena show inhibition or steady-state suppression over time. This "grow-and-shrink" view assumes that the activation levels increase fast initially and then start to decrease. The perception literature strongly suggests that it may be light intensity that determines whether mainly integration (and phenomena such as Bloch's law) or inhibition (and phenomena such as Mach-bands) is obtained. So it is also likely that both information-processing views apply only to a limited range of intensity conditions; the "grow-and-grow" view to conditions of low-light intensities, and the "grow-and-shrink" view to conditions of intermediate- and high-light intensities. It is argued that, to arrive at a complete view, a visual phenomenon that applies to the complete range of light intensities should be taken as a background for generating hypotheses about time courses in visual-information processing. The Broca-Sulzer effect is such a phenomenon. Starting from this phenomenon a simple, synthesizing, information-processing model is derived that is compatible with both the "grow-and-grow" view and the "grow-and-shrink" view.(ABSTRACT TRUNCATED AT 250 WORDS)