How drivers adapt their behaviour to changes in task complexity: The role of secondary task demands and road environment factors

The present study investigates the impact of different sources of task complexity such as driving demands and secondary task demands on driver behaviour. Although much research has been dedicated to understanding the impact of secondary task demands or specific road traffic environments on driving performance, there is little information on how drivers adapt their behaviour to their combined presence. This paper aims to describe driver behaviour while negotiating different sources of task complexity, including mobile phone use while driving (i.e., calling and texting) and different road environments (i.e., straight segments, curves, hills, tunnels, and curves on hills). A driving simulator experiment was conducted to explore the effects of different road scenarios and different types of distraction while driving. The collected data was used to estimate driving behaviour through a Generalized Linear Mixed Model (GLMM) with repeated measures. The analysis was divided into two phases. Phase one aimed to evaluate driver performance under the presence and absence of pedestrians and oncoming traffic, different lanes width and different types of distraction. The second phase analysed driver behaviour when driving through different road geometries and lane widths and under different types of distraction. The results of the experiment indicated that drivers are likely to overcorrect position in the vehicle lane in the presence of pedestrians and oncoming traffic. The effect of road geometry on driver behaviour was found to be greater than the effect of mobile phone distraction. Curved roads and hills were found to influence preferred speeds and lateral position the most. The results of this investigation also show that drivers under visual-manual distraction had a higher standard deviation of speed and lateral position compared to the cognitive distraction and the non-distraction condition.     

Exploring psychological factors of mobile phone use while riding among motorcyclists in Vietnam

Mobile phone use while riding is one of the five most common risky behaviors of motorcycle riders in Vietnam. This study investigated motorcyclist’s mobile phone use while riding intention and behavior based on the extended Theory of Planned Behavior (TPB) framework. Based on this framework, attitude, subjective norm, perceived behavioral control, habits, and health motivation underlying the rider’s mobile phone use while riding intentions and behavior were included in a questionnaire and captured by direct and indirect measurements. Small-displacement motorcycle riders (N = 291) completed the extended TPB based questionnaire. An exploratory factor analysis technique identified the selected factors (e.g., attitude, habit, etc.). Moreover, Structural Equation Modeling results showed moderate to good fits to the observed data. Therefore, the results supported the utilization of extended TPB framework in identifying factors of mobile phone use while riding intention and behavior. Specifically, negative attitude, perceived behavioral control, and mobile phone use while riding habit related to the intention to use a mobile phone while riding of small-displacement motorcyclists. Meanwhile, habit and behavioral intention related to the behavior to use a mobile phone while riding of small-displacement motorcycle riders. Especially, the correlation between behavioral intention and self-reported behavior was very strong. This finding embraced previous research indicating that intention was a major motivational component of behavior. Based on the results, safety intervention implications for small-displacement motorcycle riders were discussed.     

细菌感染性疾病中的对立统一规律与Quorum Sensing系统

引起人类细菌性感染的病原菌可以分为条件致病菌和非条件致病菌,不同性质的细菌引起的感染决定了感染矛盾的特殊性,对于不同质的矛盾,只有用不同质的方法才能解决。抗生素的发明和使用为人类控制感染性疾病的同时,这种单纯的“对抗”的解决方法也引出了一些新的矛盾。因此,细菌感染矛盾的特殊性决定我们不能采用千篇一律的“对抗斗争”形式,而必须寻求一种特殊的解决方式。对QS系统的研究发现在细菌表现致病性过程中发挥重要作用,通过QS系统减弱细菌的致病性而不杀死细菌的“抗致病性药物”来治疗感染成为一种新的抗感染思路,这种“抗致病性”概念使我们抗感染的态度从与细菌“对抗”转变为“共生”,因而QS系统可以为这种特殊矛盾提供一个合理的解决方式。     

Look: No hands! Driving on the motorway

How drivers hold their steering wheels when they are driving has been studied in restricted ways for many years. Here I describe the advantages (and disadvantages) of a more naturalistic way of studying this phenomenon, and present the results from two studies that observed the hand positions of motorway drivers from an elevated vehicle. In the first study I tape-recorded the data as we passed traffic on the left, and in the second I used paper and pencil to record the data as traffic passed us on the right. In both studies few drivers kept to the recommended 10-2 (or more generous 9-3) position for holding the steering wheel, and approximately one-third of them were driving with one hand on the wheel. Very few of the drivers observed (some 2%) were using mobile phones, but two were driving with no hands on the wheel. The paper concludes with some discussion of the value of this methodology for obtaining realistic data.     

Even experienced phone users drive worse while texting – A driving simulator study

Several studies have clearly shown that texting on a mobile phone increases crash risk (e.g. Dingus et al., 2006; Victor et al., 2014). However, the frequency of texting while driving still remains high (e.g. Vollrath, Huemer, Teller & Likhacheva, 2016). One reason may be that drivers are convinced that they are able to manage this dual task due to their competency in driving and texting. From a theoretical point of view, this may be true within limits – two well-learned, automatically processed tasks may require so few resources most of the time that interferences may not occur.In order to test this assumption, a study with a standardized driving simulator task (the lane change task, LCT; Mattes, 2003) was done with n = 40 drivers selected for their driving experience and tested for their texting abilities. The effect of driving experience (high vs. low) and texting competence (high vs. low) on driving performance was examined in single (driving only) and dual-task (driving and texting) conditions. Additionally, a subjective assessment of one’s task performance was obtained. Texting on the mobile phone significantly impaired driving performance. While driving experience did not have an influence, the deteriorating effect of texting was significantly less pronounced in highly competent phone users. Interestingly, this objective effect was not found in the subjective assessment. Drivers with a high texting competence felt as impaired as drivers with a low texting competence. This is in line with the finding that even in this simple driving task their performance was still significantly deteriorated as compared to driving, only. Thus, it seems that the reason why people text while driving is not that they are not aware of the performance loss. However, this awareness of the possible risk does not seem sufficient to prevent them from texting while driving.     

Modeling the influence of mobile phone use distraction on pedestrian reaction times to green signals: A multilevel mixed-effects parametric survival model

Understanding and modeling the influence of mobile phone use on pedestrian behaviour is important for several safety and performance evaluations. Mobile phone use affects pedestrian perception of the surrounding traffic environment and reduces situation awareness. This study investigates the effect of distraction due to mobile phone use (i.e., visual and auditory) on pedestrian reaction time to the pedestrian signal. Traffic video data was collected from four crosswalks in Canada and China. A multilevel mixed-effects accelerated failure time (AFT) approach is used to model pedestrian reaction times, with random intercepts capturing the clustered-specific (countries) heterogeneity. Potential reaction time influencing factors were investigated, including pedestrian demographic attributes, distraction characteristics, and environment-related parameters. Results show that pedestrian reaction times were longer in Canada than in China under the non-distraction and distraction conditions. The auditory and visual distractions increase pedestrian reaction time by 67% and 50% on average, respectively. Pedestrian reactions were slower at road segment crosswalks compared to intersection crosswalks, at higher distraction durations, and for males aged over 40 compared to other pedestrians. Moreover, pedestrian reactions were faster at higher traffic awareness levels.     

A systematic review of observational studies investigating the influence of mobile phone distraction on road crossing behaviour of pedestrians

The growing prevalence of technological distractions amongst pedestrians makes it an important road safety concern. Observational studies are considered a reliable method to investigate the influence of mobile phone distraction on pedestrian road crossing behaviour and crash risks. The present study conducts a systematic review of international literature on pedestrian distraction observations by following the Preferred Reporting Items for Systematic Reviews and meta-Analyses (PRISMA) guidelines. A total of 792 studies were identified from the literature search on six research databases: Scopus, Google Scholar, Web of Science, PubMed, Cochrane library, and Transportation Research International Documentation (TRID). Finally, 39 research articles were assessed using the systematic classification scheme based on the following five research aspects: prevalence of mobile phone distraction, study locations, performance measures, analysis techniques, and additional factors associated with mobile phone use among pedestrians. Over 35% of the studies were conducted in the United States of America (USA) and 69% of the investigations were done in the last five years. Overall, the findings across the studies indicate that mobile phone distraction plays a major role in pedestrian risky road crossing behaviour and violation tendencies. Visual distractions (such as texting) exhibited higher behavioural impairment compared to cognitive distractions (e.g., listening to music, and conversations). Pedestrian characteristics such as gender and age were the key factors examined in 77% and 67% of the observational studies. Finally, important directions for future research are illustrated to aid the researchers working in the area of pedestrian safety.     

The Relationship of Mobile Telephony to Job Mobility in China’s Pearl River Delta

In southern China, the use of mobile phones is becoming a ubiquitous part of everyday life for young migrant workers. What could be the possible relationship between mobile telephony and job mobility among migrants? A study of 655 migrant workers conducted in 2006 in the Pearl River Delta found a relationship between job change among migrant workers and the increasing use of mobile phones due to more information on jobs with better pay and working conditions being sent to them by friends, former coworkers, and clansmen. However, this portrait of migrant worker e-actors operating in a “broadband information society” can only be viewed in the context of the migrant labor shortage in southern China since 2004. Of fundamental concern are the vagrant identities of this new generation of young migrant workers who are excluded from the host society in which they work but also feel uncomfortable with their farmer status in their home towns.     

手持移动用户界面显示效果的工效学研究

手持移动界面功效是小屏幕显示界面设计关注的主要问题之一,本研究采用实验和问卷调查相结合的方法,探讨手机界面的前景和背景颜色搭配、界面呈现方式(图标或文字)等对手持界面操作效率的影响。研究结果表明,前景和背景颜色搭配对手持界面操作效率有显著影响,界面呈现方式对操作效率有一定影响,但没有达到显著水平,问卷调查结果与实验结果存在一致性。     

Designing Mobile Systems in Highly Dynamic Scenarios: The WORKPAD Methodology

The design of interactive systems to be used in mobile and pervasive scenarios, such as emergency management, requires novel methodologies which combine user-centred design approaches and software engineering approaches tailored for distributed architectures. In this paper, the methodology adopted in a successful research project is presented together with a case study.