Driver hand-held cellular phone use: a four-year analysis

INTRODUCTION: The use of hand-held cellular (mobile) phones while driving has stirred more debate, passion, and research than perhaps any other traffic safety issue in the past several years. There is ample research showing that the use of either hand-held or hands-free cellular phones can lead to unsafe driving patterns. Whether or not these performance deficits increase the risk of crash is difficult to establish, but recent studies are beginning to suggest that cellular phone use elevates crash risk. METHODS: The purpose of this study was to assess changes in the rate of hand-held cellular phone use by motor-vehicle drivers on a statewide level in Michigan. This study presents the results of 13 statewide surveys of cellular phone use over a 4-year period. Hand-held cellular phone use data were collected through direct observation while vehicles were stopped at intersections and freeway exit ramps. Data were weighted to be representative of all drivers traveling during daylight hours in Michigan. RESULTS: The study found that driver hand-held cellular phone use has more than doubled between 2001 and 2005, from 2.7% to 5.8%. This change represents an average increase of 0.78 percentage points per year. The 5.8% use rate observed in 2005 means that at any given daylight hour, around 36,550 drivers were conversing on cellular phones while driving on Michigan roadways. The trend line fitted to these data predicts that by the year 2010, driver hand-held cellular phone use will be around 8.6%, or 55,000 drivers at any given daylight hour. CONCLUSIONS: These results make it clear that cellular phone use while driving will continue to be an important traffic safety issue, and highlight the importance of continued attempts to generate new ways of alleviating this potential hazard.     

Dissociation between driving performance and drivers' subjective estimates of performance and workload in dual-task conditions

Introduction

The current study measured how concurrent driving and in-vehicle activities of different levels of engagement varied in terms of performance and subjective estimates of demand and performance.

Method

In this test track study, 41 younger and older drivers completed a series of cognitive tasks while driving an instrumented vehicle. One task involved an engaging guessing game where drivers tried to guess the identity of an object. The other task involved a simple mental arithmetic task.

Results

We observed some dissociation between drivers' performance and their subjective reports. For instance, drivers tended to estimate their performance as better for the more engaging guessing task than the arithmetic task, though their performance was actually worse. At the same time, subjective estimates of workload across the two tasks did not vary in the dual-task condition even though they did in the single-task baseline conditions, suggesting that drivers failed to account for the added demands in dual-task situations.

Conclusions

We discuss the implications of these findings for driver safety.

Impact on Industry

Crashes due to distraction can carry tremendous costs for employers, in terms of injury, disability, and loss of potentially productive work years, whether these crashes occur on or off the job.     

Classification of driving workload affected by highway alignment conditions based on classification and regression tree algorithm

Objective: Guaranteeing a safe and comfortable driving workload can contribute to reducing traffic injuries. In order to provide safe and comfortable threshold values, this study attempted to classify driving workload from the aspects of human factors mainly affected by highway geometric conditions and to determine the thresholds of different workload classifications. This article stated a hypothesis that the values of driver workload change within a certain range.

Methods: Driving workload scales were stated based on a comprehensive literature review. Through comparative analysis of different psychophysiological measures, heart rate variability (HRV) was chosen as the representative measure for quantifying driving workload by field experiments. Seventy-two participants (36 car drivers and 36 large truck drivers) and 6 highways with different geometric designs were selected to conduct field experiments. A wearable wireless dynamic multiparameter physiological detector (KF-2) was employed to detect physiological data that were simultaneously correlated to the speed changes recorded by a Global Positioning System (GPS) (testing time, driving speeds, running track, and distance). Through performing statistical analyses, including the distribution of HRV during the flat, straight segments and P-P plots of modified HRV, a driving workload calculation model was proposed. Integrating driving workload scales with values, the threshold of each scale of driving workload was determined by classification and regression tree (CART) algorithms.

Results: The driving workload calculation model was suitable for driving speeds in the range of 40 to 120 km/h. The experimental data of 72 participants revealed that driving workload had a significant effect on modified HRV, revealing a change in driving speed. When the driving speed was between 100 and 120 km/h, drivers showed an apparent increase in the corresponding modified HRV. The threshold value of the normal driving workload K was between ?0.0011 and 0.056 for a car driver and between ?0.00086 and 0.067 for a truck driver.

Conclusion: Heart rate variability was a direct and effective index for measuring driving workload despite being affected by multiple highway alignment elements. The driving workload model and the thresholds of driving workload classifications can be used to evaluate the quality of highway geometric design. A higher quality of highway geometric design could keep driving workload within a safer and more comfortable range. This study provided insight into reducing traffic injuries from the perspective of disciplinary integration of highway engineering and human factor engineering.     

The combined effects of on-road and simulator training with feedback on older drivers' on-road performance: Evidence from a randomized controlled trial

Objective: A number of training programs that seek to improve driving performance among older drivers are available accompanied by a growing interest in their effectiveness. The purpose of the present investigation was to examine the combined effect of (1) basic in-class training (BT); (2) on-road training with individualized feedback (OR); and (3) training on a driving simulator (S).

Methods: Using a randomized controlled trial study design, 78 older drivers were randomly assigned to one of 3 groups (BT, BT + OR, or BT + OR + S). All participants completed a pre- and postintervention on-road driving evaluation on a standardized route. The driving evaluations were recorded using video and Global Positioning System (GPS) equipment and were scored by a blind assessor.

Results: The results indicated a significant reduction of approximately 30% in overall number of driving errors/omissions among participants in the BT + OR and the BT + OR + S groups in comparison to participants in the BT group.

Conclusions: This study adds to the mounting evidence demonstrating the effectiveness of individualized driver training in improving safe driving among older adults.     

电脑使用工效学评价方法的研究：键盘和鼠标使用及人体疲劳

为了进行电脑相关肌肉骨骼疾病（Computer Related Musculoskeletal Disorders）的办公室工效学研究,需要研发更有效的电脑使用工效学评价方法。鉴于键盘和鼠标是电脑操作者最主要的输入工具,而且高重复性的操作动作会增加患肌肉骨骼疾病的风险,为了保护电脑操作者的职业健康,本研究研发一套键盘和鼠标使用的工效学评价方法并且使用该评价方法评价键盘和鼠标的使用以及使用过程中的人体疲劳。评价方法设计包括：＂键盘鼠标使用统计软件＂、＂疲劳问卷系统软件＂和数据处理和结果可视化。应用此评价方法对25个对象进行了8周的纵向观察与评价。键盘鼠标使用的评价结果能够准确反映评价对象操作键盘鼠标的实际情况;对疲劳程度的分析结果也与实验室研究结论一致,得到了理论支持,成功研发了一套创新、有效的电脑键盘和鼠标使用的工效学评价方法。     

Bicycle helmet use among children in the United States: The effects of legislation, personal and household factors

Introduction

Children ages 5-14 years have the highest rate of bicycle-related injuries in the country. Bicycle helmets can prevent head and brain injuries, which represent the most serious type of bicycle-related injury.

Objectives

This paper compares children's bicycle helmet use to that estimated from an earlier study, and explores regional differences in helmet use by existing helmet legislation.

Methods

This study was a cross-sectional, list-assisted random-digit-dial telephone survey. Interviews were completed by 9,684 respondents during 2001-2003. The subset with at least one child in the household age 5-14 years (2,409 respondents) answered questions about bicycle helmet use for a randomly selected child in their household.

Results

Almost half (48%) of the children always wore their helmet, 23% sometimes wore their helmet, and 29% never wore their helmet. Helmet wearing was significantly associated with race, ethnicity, and child age but was not associated with the sex of the child. Other significant predictors of use included household income, household education, census region, and bicycle helmet law status. Statewide laws were more effective than laws covering smaller areas. The proportion of children who always wore a helmet increased from 25% in 1994 to 48% in 2001-2002. Significant increases in helmet use from 20% to 26% were seen among both sexes, younger (5-9 years) and older (10-14 years) children, and in all four regions of the country.

Conclusions

While there has been substantial progress in the number of children who always wear their helmets, more than half do not. Further progress will require using a combination of methods that have been shown to successfully promote consistent helmet use. Impact on industry: minimal.     

The interactive effects of conscientiousness,openness to experience,and political skill on job performance in complex jobs: The importance of context

Caveats concerning the ability of personality to predict job performance have been raised because of seemingly modest criterion‐related validity. The goal of the present research was to test whether narrowing the context via the type of job (i.e., jobs with complex task demands) and adding a social skill‐related moderator (i.e., political skill) would improve performance prediction. Further, along with political skill, the broad factor of personality demonstrated in prior research to have the strongest criterion validity (i.e., conscientiousness) was joined with a narrow construct closely related to openness to experience (i.e., learning approach) in a three‐way interactive prediction of supervisor‐rated task performance. With the employee–supervisor dyads among professionals, but not with the control group of non‐professional employees, task performance was predicted by the three‐way interaction, such that those high on all three received the highest performance ratings. Implications, strengths and limitations, and directions for future research are discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

[Case Study] CityCenter and Cosmopolitan Construction Projects, Las Vegas, Nevada: Lessons learned from the use of multiple sources and mixed methods in a safety needs assessment

Problem

The present study describes a response to eight tragic deaths over an eighteen month times span on a fast track construction project on the largest commercial development project in U.S. history.

Methods

Four versions of a survey were distributed to workers, foremen, superintendents, and senior management. In addition to standard Likert-scale safety climate scale items, an open-ended item was included at the end of the survey.

Results

Safety climate perceptions differed by job level. Specifically, management perceived a more positive safety climate as compared to workers. Content analysis of the open-ended item was used to identify important safety and health concerns which might have been overlooked with the qualitative portion of the survey.

Discussion

The surveys were conducted to understand workforce issues of concern with the aim of improving site safety conditions. Such efforts can require minimal investment of resources and time and result in critical feedback for developing interventions affecting organizational structure, management processes, and communication.

Summary

The most important lesson learned was that gauging differences in perception about site safety can provide critical feedback at all levels of a construction organization.

Impact on the Industry

Implementation of multi-level organizational perception surveys can identify major safety issues of concern. Feedback, if acted upon, can potentially result in fewer injuries and fatal events.