Are car daytime running lights detrimental to motorcycle conspicuity?

Improving motorcycle motion perception by using innovative motorcycle headlight configurations: Evidence from simulator and test-track experiments

Many motorcycle accidents occur at intersections and are caused by other vehicle drivers who misperceive the speed and time-to-arrival of an approaching motorcycle. The two experiments reported here tested different motorcycle headlight configurations likely to counteract this perceptual failure. In the first experiment, conducted on a driving simulator, car drivers turned left in front of cars and motorcycles approaching an intersection under nighttime lighting conditions. The motorcycles were equipped with either a standard white central light, or one of three vertical configurations of white and yellow lights. The results showed that the standard configuration led to significantly more unsafe accepted gaps than the vertical configurations. In the second experiment, conducted on a test track using a similar task, the most promising motorcycle headlight configuration, i.e., the vertical yellow-white light arrangement (one central white light, plus one yellow light on the helmet and two yellow lights on the fork) was evaluated and compared to a standard configuration and a car. The vertical yellow-white headlight configuration again provided significant safety benefits as compared to the standard configuration. These findings demonstrate that motorcycle safety can be improved by headlight ergonomics that accentuate the vertical dimension of motorcycles. They also suggest that the driving simulator is a valid tool for conducting research on motorcycle headlight design.

Effects of taillight shape on conspicuity of vehicles at night

Taillight shape in a vehicle provides an essential lighting signal that enables the vehicle to be seen from the rear at night, thereby preventing rear-end crashes. This study aims to investigate the effects of taillight shape on vehicle conspicuity, and proposes ergonomic taillight shape solutions to vehicle designers and manufacturers. Two complementary experiments were conducted to examine three types of taillight shapes at three design levels. The first experiment was designed to investigate the detection speed of a driver and the fixation duration and fixation counts on leading vehicles with different taillight shapes, based on an eye-tracking methodology. The second experiment was designed to investigate the dynamic visual searching performance of a trailing driver for leading vehicles with different taillight shapes, based on a visual search task. The experimental results indicated that a long line-shaped taillight (striplight) was the optimal ergonomic solution for enhancing vehicle conspicuity. Vehicles with an enclosed contour-shaped taillight were more salient than those with an open contour-shaped taillight. Moreover, the experience and gender of the driver and the vehicle-observer distance were found to be closely related to vehicle conspicuity, and therefore, must be considered by vehicle designers when applying a specific taillight shape design. This study provides insights into the taillight shape design that not only aid vehicle designers or manufacturers in enhancing vehicle safety but also enable potential vehicle buyers to choose a safe lighting system.

Motorcycle Conspicuity Issues and Intervention: A Systematic Review

Background

Conspicuity has been one of the key factors in motorcycle road crashes around the world. The inability and difficulty of other road users in detecting motorcycles either at day or at night have contributed to conspicuity related motorcycle crashes. This literature review attempts to understand the motorcycle conspicuity issues in road traffic. The review also analyses relevant types of conspicuity intervention in terms of its effectiveness in enhancing motorcycle conspicuity that had been discussed in past studies.

Methods

Using specific keywords and search terms, relevant articles were screened, identified and analyzed systematically using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results

Twenty-seven final articles were reviewed and found that almost every part of motorcycle and motorcyclist's conspicuity intervention have been covered in past studies. In terms of conspicuity aids, the majority of past studies discussed conspicuity enhancement in the frontal area, particularly on motorcycle daytime running headlight (DRH) color and configurations. Few other studies have discussed in other areas, particularly on rear running and brake light and motorcycle color. There were also numerous studies looking at motorcyclists' appearances in terms of their attire and helmet color.

Conclusion

Motorcycle and motorcyclist's appearances are highly associated with the risk of motorcycle crashes. The most important part of enhancing motorcycle conspicuity is to ensure motorcycle appearance is always in contrast with the road traffic environment.

An application of the theory of planned behaviour to understand compliance with daytime running headlights law among motorcycle riders

Fatal motorcycle crashes are a persistent problem in Southeast Asia. In many respects, road safety experts have acknowledged conspicuity issue as one of the main causes of such accidents. To mitigate this deficiency, daytime running headlights (DRHs) law has been documented among the widely exercised countermeasures. The present study aimed to explore socio-psychological factors shaping intentions towards use of DRHs among Malaysian motorcyclists, because compliance level with this rule has remained constant since 1996 (80%). For this purpose, a model was constructed through the Theory of Planned Behaviour (TPB) to evaluate factors affecting motorcyclists' intentions towards compliance with DRHs law. A series of statistical analyses were performed to explain the effect of these factors and to predict degree of compliance with this rule. The model applied on a sample of university students (N = 398) demonstrated that the TPB components could significantly predict motorcycle riders' behaviours and degree of compliance with DRHs law. Moreover, it would be of assistance to policy-makers to recognize groups of motorcyclists more likely to cause an increase in traffic accidents. In general, regular educational campaigns were recommended to raise awareness regarding consequences of not using DRHs and also to nurture factors influencing motorcyclists' attitudes towards DRHs.

On the Dynamics of Conspicuity

OBJECTIVE

To examine the influences of dynamic conspicuity on object recognition and to evaluate the real-world implications of these processes.

BACKGROUND

Conspicuity is the major influence on persons' abilities to recognize the presence of entities within their environment. Shortfalls in sensory and cognitive conspicuity are implicated in many, if not most, real-world systemic failures.

METHOD

The present observations derive from an overview of relevant empirical research allied to a synthetic integration. From these foundations, I articulate a proposed taxonomy through which to parse the essential dimensions of conspicuity.

RESULTS

The taxonomy features three axes related to (a) modality (e.g., visual vs. auditory, etc.), (b) processing directionality (e.g., top-down vs. bottom-up information flow), and finally (c) temporality (i.e., the differences between static vs. dynamic presentations).

CONCLUSION

Existing conspicuity studies have primarily featured static, sensory comparisons. Exploration of the other quadrants of the proposed taxonomy can serve to frame future conspicuity research. This taxonomic description also provides the basis from which to understand failure etiology in a wide spectrum of human-machine systems.

APPLICATION

Improvements in the understanding of conspicuity can help in all domains of HF/E and can serve to reduce failure in a wide variety of operational contexts.

The effect of lighting conditions and use of headlights on drivers' perception and appraisal of approaching vehicles at junctions

Use of Daytime Running Lights (DRL) is mandatory in many countries for motorcycles, and in some for cars. However, in developing countries, DRLs may be optional or compliance low. The effect of car or motorcycle headlights and lighting conditions on Malaysian drivers' ability to perceive and judge the safety of pulling out was investigated. Stimuli were photographs depicting either daytime or nighttime taken at a T-junction with approaching vehicles with headlights on or off. Headlights improved drivers' ability to perceive cars and motorcycles in the nighttime photographs but not the daytime photographs, although this could be due to the bright weather in the photographs. Drivers judged it less safe to pull out when approaching motorcycles had headlights on than off, regardless of the lighting conditions, supporting the utility of DRL for motorcycles. Headlights did not affect judgements for cars, questioning the utility of DRL for cars. Practitioner Summary: The effect of headlights and lighting conditions on drivers' ability to perceive and make judgements about the safety of pulling out was investigated. Daytime Running Lights influenced drivers' decision-making about the safety of pulling out in front of motorcycles, illustrating the importance of having automatic headlights equipped.

Do cyclists make better drivers? Associations between cycling experience and change detection in road scenes

Efficient processing of visual information is crucial to safe driving. Previous research has demonstrated that driving experience strongly affects attentional allocation, with large differences between novice and experienced drivers. Expanding on this, we explored the influence of non-driving experiences on attentional allocation by comparing drivers with and without cycling experience. Based on situation awareness field studies, we predicted cyclist-drivers would demonstrate superior performance. Participants were 42 experienced drivers (17 female, 25 male) aged 30-50 years (M=39.8): 20 drivers and 22 cyclist-drivers. The experiment used a change detection flicker task, in which participants must determine whether two alternating images are identical (change-absent) or differ in a single detail (change-present). The changed object was either a road sign, car, pedestrian, or bicycle. Change target significantly affected both accuracy and response time: all participants were slower and less accurate at detecting changes to road signs, compared with when the change was a moving road user (i.e., car, pedestrian, bicycle). Accuracy did not differ significantly between groups, but cyclist-drivers were significantly faster than drivers at identifying changes, with the effect being largest for bicycle and sign changes. The results suggest that cycling experience is associated with more efficient attentional processing for road scenes.

Improving motorcycle conspicuity through innovative headlight configurations

Most motorcycle crashes involve another vehicle that violated the motorcycle's right-of-way at an intersection. Two kinds of perceptual failures of other road users are often the cause of such accidents: motorcycle-detection failures and motion-perception errors. The aim of this study is to investigate the effect of different headlight configurations on motorcycle detectability when the motorcycle is in visual competition with cars. Three innovative headlight configurations were tested: (1) standard yellow (central yellow headlight), (2) vertical white (one white light on the motorcyclist's helmet and two white lights on the fork in addition to the central white headlight), and (3) vertical yellow (same configuration as (2) with yellow lights instead of white). These three headlight configurations were evaluated in comparison to the standard configuration (central white headlight) in three environments containing visual distractors formed by car lights: (1) daytime running lights (DRLs), (2) low beams, or (3) DRLs and low beams. Video clips of computer-generated traffic situations were displayed briefly (250ms) to 57 drivers. The results revealed a beneficial effect of standard yellow configuration and the vertical yellow configuration on motorcycle detectability. However, this effect was modulated by the car-DRL environment. Findings and practical recommendations are discussed with regard to possible applications for motorcycles.

Motorcyclist's lane position as a factor in right-of-way violation collisions: a driving simulator study

A driver turning left and failing to notice an oncoming motorcyclist until too late is the most common cause of motorcycle collisions. Consequently, much previous research has focused on motorcycle properties, such as size, shape, and color to explain its inconspicuousness. However, collision statistics remain largely unchanged, suggesting that the issue may not be related solely to the motorcycle's static properties. In the present study, we examined a different characteristic of the motorcycle, namely its trajectory of approach. Seventeen participants faced oncoming traffic in a high-fidelity driving simulator and indicated when gaps were safe enough for them to turn left at an intersection. We manipulated the size of the gaps and the type of oncoming vehicle over 135 trials, with gap sizes varying from 3 to 5s, and vehicles consisting of either a car, a motorcycle in the left-of-lane position, or a motorcycle in the right-of-lane position. Our results show that drivers are more likely to turn in front of an oncoming motorcycle when it travels in the left-of-lane position than when it travels in the right-of-lane position.

A review of powered-two-wheeler behaviour and safety

Powered-two-wheelers (PTWs) constitute a very vulnerable type of road users. The notable increase in their share in traffic and the high risk of severe accident occurrence raise the need for further research. However, current research on PTW safety is not as extensive as for other road users (passenger cars, etc.). Consequently, the objective of this research is to provide a critical review of research on Power-Two-Wheeler behaviour and safety with regard to data collection, methods of analysis and contributory factors, and discuss the needs for further research. Both macroscopic analyses (accident frequency, accident rates and severity) and microscopic analyses (PTW rider behaviour, interaction with other motorised traffic) are examined and discussed in this paper. The research gaps and the needs for future research are identified, discussed and put in a broad framework. When the interactions between behaviour, accident frequency/rates and severity are co-considered and co-investigated with the various contributory factors (riders, other users, road and traffic environment, vehicles), the accident and injury causes as well as the related solutions are better identified.

Influence of front light configuration on the visual conspicuity of motorcycles

A recent study (Cavallo and Pinto, 2012) showed that daytime running lights (DRLs) on cars create "visual noise" that interferes with the lighting of motorcycles and affects their visual conspicuity. In the present experiment, we tested three conspicuity enhancements designed to improve motorcycle detectability in a car-DRL environment: a triangle configuration (a central headlight plus two lights located on the rearview mirrors), a helmet configuration (a light located on the motorcyclist's helmet in addition to the central headlight), and a single central yellow headlight. These three front-light configurations were evaluated in comparison to the standard configuration (a single central white headlight). Photographs representing complex urban traffic scenes were presented briefly (for 250ms). The results revealed better motorcycle-detection performance for both the yellow headlight and the helmet configuration than for the standard configuration. The findings suggest some avenues for defining a new visual signature for motorcycles in car-DRL environments.

Can a road safety measure be both effective and ineffective at the same time? A game-theoretic model of the effects of daytime running lights

Studies that have evaluated the effects on accidents of daytime running lights for cars have consistently found that cars using daytime running lights are involved in fewer multi-party accidents in daylight than cars not using daytime running lights. However, studies evaluating the effects of mandatory use of daytime running lights have not always found an accident reduction. Although findings are mixed, there is a tendency for the aggregate effects of daytime running lights (i.e. the effects of an increasing share of traffic using daytime running lights) to be smaller than the intrinsic effects (i.e. the difference in accident involvement between cars using and not using daytime running lights). This paper presents a game-theoretic model to explain these apparently inconsistent findings. The game-theoretic model is based on so called Schelling-diagrams, originally introduced by Nobel laureate in economics Schelling. The effects of daytime running lights are modelled by means of Schelling-diagrams. It is shown that it is by no means impossible for cars using daytime running lights to always be safer than cars not using daytime running lights, while the total number of accidents remains constant even if the percentage of cars using daytime running lights increases from, say, 10% to 90%.