A performance analysis of In-Car Music engagement as an indication of driver distraction and risk

Drivers engage in a host of driving-unrelated tasks while on the road. They listen to music, sing-along, and accompany songs by pounding-out drum-kicks and syncopated rhythms on the steering wheel. However, there is controversy over in-cabin music: Does background music facilitate driver performance via increased arousal leading to more focused concentration, or cause distraction placing drivers at greater risk. In an effort to shed light on the debate, the current study evaluated music engagement by employing Music Performance Analyses with audio recordings from three simulated driving conditions. The results indicate that as the perceptual demands of the primary driving task increased, the secondary music activity was hampered, and subsequently sub-optimal vocal and percussive performances were demonstrated consisting of intonation errors, rhythmic inaccuracy, lack of synchrony, inconsistent and unstable temporal flow, neglect of text, and lyric replacement. The findings seem to point out that drivers allocate greater reserves to music than previously considered, and as drivers do not withdraw altogether from music engagement under high-demand driving conditions, driving may be under-resourced. Exploring active music engagement while driving might assist traffic safety researchers in decoding the effects of In-Car Music on driver behavior.     

The effect of driver improvement interventions on crash involvement; has it been under-estimated?

The available evidence suggests that driver improvement interventions (with the aim to increase driver safety, most often by education or training) do not work. The average effect calculated in several meta-analyses is close to, and not always possible to distinguish from, zero, despite total samples sizes of several hundred thousand drivers. However, it is possible that all studies included in these meta-analyses have under-estimated the effect, due to a methodological error; all crashes have been used as dependent variable, instead of only those that the targeted drivers have caused. This error is expected to have considerably deflated the effect sizes, but it is not known how large this effect could be.Using crash data for bus drivers in which culpability had been reliably established, a simple simulation was performed to determine the difference between using culpable and all crashes as an estimator of a safety effect. Using data for six years, calculations were made on single years. About ten percent of culpable crashes in each year were deleted to simulate a safety effect, where after the difference between the original and the simulated variable were calculated, using culpable only and all crashes in parallel. The effects using these two different kinds of datasets could then be compared and the under-estimation effect estimated.Culpable crashes, as compared to all crashes, yielded larger differences in means between time periods, and smaller standard deviations. In between-subjects comparisons resulted in 15–30 percent larger effects for culpable crashes. Within-subjects calculations yielded larger but not as systematic effects.The effect of driver improvement on crash involvement has been systematically under-estimated, as extremely few evaluation studies seem to have taken culpability for crashes into account. Therefore, new evaluations need to be undertaken, and/or old data re-analysed, to calculate a better estimate of the true effect of training and education in driving safety.     

Investigation of drivers’ thresholds of a subjectively accepted driving performance with a focus on automated driving

Lately, the development and implementation of automated driving moved to the center of interest in the automotive industry. In this context, one of the central issues – the configuration of adequate trajectories – is mainly tackled using a technical approach. However, it appears that a technically ideal driving performance does not necessarily coincide with the drivers’ subjective preferences. This study strives to determine thresholds of a subjectively accepted driving performance regarding lateral vehicle control. A second objective is to analyze the influence of selected personal and situational factors on these thresholds. An empirical online survey with 161 participants rating video sequences of driving performances was conducted. The video sequences differed not only with regard to the lateral offset of the ego-vehicle but also concerning the weather (sun/rain) and traffic conditions (existence/driving behavior of oncoming traffic). Additionally, the participants’ driving experience and sensation seeking were considered in the data evaluation. To analyze the data, binary logistic regression analyses were calculated. They revealed that the subjective evaluation of driving performances varies primarily depending on the lateral offset of both the ego-vehicle and the oncoming traffic. The results indicate that regarding the lateral offset certain thresholds of subjectively accepted driving performances do exist. Regarding the development of automated driving systems, two issues need to be considered in order to ultimately guarantee user acceptance. First, the subjective thresholds need to be integrated into the systems’ trajectory planning. Second, the oncoming traffic’s driving behavior has to be considered.     

Effects of Share the Keys (STK), a comprehensive,behavioral-based training program for parents and new teen drivers in New Jersey

The New Jersey Graduated Driver License (GDL) restrictions were updated in 2010 with changes that included a more active role of parents monitoring practice driving with their teens. In addition to extending the driving phases, there were new curfew and passenger limit restrictions. Teen drivers were also required to use red decals on license plates to identify themselves as inexperienced drivers. The Division of Highway Traffic Safety had partnered with the Motor Vehicle Commission in the past to produce practice driving guides for parents of teen drivers, but recognized the need to support this type of informational campaign with an educational program for helping parents to understand changes in the GDL and recognize the importance of their role in the GDL monitoring process. In 2010, the New Jersey Parent/Teen Driver Orientation program was developed to educate parents of teen drivers on the new GDL restrictions and Children’s Hospital of Philadelphia (CHOP) findings concerning the importance of parenting roles in teen driver safety. Additional resources were incorporated into the orientation that included the Centers for Disease Control (CDC) community based information and the University of Michigan Transportation Research Institute (UMTRI) parent-teen driver contracts.This community-based training, known as the New Jersey Parent/Teen Driver Orientation was later renamed Share the Keys, and had been developed for the state as a component of the New Jersey Highway Safety grant received by Kean University. The comprehensive program was designed to engage parents, teens, educators, and law enforcement in the teen driving process and help parents to understand how personal parenting styles and engagement may impact teen crash risk and compliance with the GDL restrictions. Local representatives from traffic safety and law enforcement teamed with school officials and driver education teachers to present programs in their communities. The evaluation process was built into the program as a pre-survey administered at the beginning of the session, a post-survey completed directly afterward, and a voluntary follow-up survey completed on line or mailed, beginning six months later.Evidence from the first year showed that parents maintained a significant level of engagement throughout the GDL process with their teen drivers. However, findings did establish the need to further examine why Authoritative parenting styles had declined, especially since this parenting approach was considered in the literature as most effective in reducing teen crash risks. Therefore, the scope of this study was broadened to a three year effort that reached over 2800 parents and investigated behavioral outcomes impacted by Share the Keys. While comparisons made between driving phases and parenting styles had yielded no significant results, changes within parenting style scores were shown to be effective over time. The reported levels of Permissive and Uninvolved parents remained consistent throughout all three driving phases, while Authoritarian parenting peaked during the Probationary phase, and Authoritative parenting was noted as highest once teens earned their license.     

The relationship between ADHD symptoms and driving behavior in college students: The mediating effects of negative emotions and emotion control

Previous research has shown a relationship between attention deficit-hyperactivity disorder (ADHD) symptoms and driving anger and adverse driving outcomes. Moreover, adults with ADHD symptoms express their emotions in more aggressive ways, indicating a lack of emotion control. The present study surveyed 246 college students to examine the relationship among ADHD symptoms, negative emotions, emotion control, and driving anger and safe driving behavior. Mediating effects of negative emotions and emotional control on the relationship between ADHD symptoms and self-reported driving anger and safe driving behavior were also examined. Both negative emotions and emotion control were significant mediators of the relationship between ADHD symptoms and driving anger, but not safe driving behavior. Mediation was stronger for ADHD-Hyperactive/Impulsive symptoms than for ADHD-Inattention symptoms. These results may provide some insight on how to design training programs for individuals with ADHD symptoms to increase driving safety.     

User-related assessment of a Driver Assistance System for Continuous Support – A field trial

A Driver Assistance System for Continuous Support continuously evaluates the status of the host vehicle as well as the surrounding traffic based on information from on-board sensors. When the system detects a hazard, it issues a warning to the driver, depending on the degree of the hazard. The effects of this system on driver behaviour and acceptance were evaluated in a field trial carried out in 2013. Twenty-four drivers took part in test drives with a within-subject design along a 53 km test route containing motorway and rural-road sections. Driving data was logged and the test drivers were observed by means of an in-car observation method (Wiener Fahrprobe); in this case by two observers in the car along with the driver. Questionnaires were used to assess the drivers’ comprehension of and reaction to the system. The system was successful in affecting driver behaviour in terms of lower speed when negotiating curves. Positive effects were found in the form of better speed adaptation to the situation during driving with the system activated. Also, lane choice and lane change improved with the system on. When it came to speed limit compliance, driving speed in general and longitudinal and lateral positioning, no effects could be found. No major differences were found regarding distance to the vehicle in front, overtaking manoeuvres, stopping behaviour at intersections, driving against yellow at traffic lights and interaction behaviour with other road users while driving with or without the system. On the negative side, it was noted that only during driving with the system activated did the test drivers make turns at intersections at too high speeds. In addition, more errors associated with dangerous distance to the side were observed with the system activated. In terms of the emotional state of the driver, the only difference found was that the drivers felt an increase in irritation. Regarding subjective workload, the drivers only assessed one item, i.e. whether their performance decreased statistically significantly while driving with the system. The test drivers were of the opinion that the system was useful, and that it would enhance safety especially in overtaking manoeuvres on motorways. The blind-spot warning was found especially useful in the overtaking process. The drivers appreciated the fact that the system did not give information all the time.     

Valid representation of a highly dynamic collision avoidance scenario in a driving simulator

In Germany the second-most frequent accidents in road traffic are rear-end collisions. For this reason rear-end collisions are quite important for accident research and the development of driving safety systems. To examine the functionality and to design the human–machine-interface of new driving safety systems, especially in the early development phase, subject tests are necessary. Because of the great hazard potential of such safety critical scenarios for the test persons, they are often conducted in a driving simulator (DS). Accordingly, validity is an important qualification to ensure that the findings collected in a simulated test environment can be directly transferred to the real world.This paper regards the question of driving behavior validity of DS in critical situations. There are hardly any validation studies which analyze the driving behavior in a specific collision avoidance situation.The validation study described in this paper aims to evaluate the behavioral validity of a fixed-base simulator in a collision avoidance situation. For this reason a field study from 2007 was replicated in a fixed-base simulator environment.The main questions of this validation study were if the driver can notice an active hazard braking system and if the driving behavior in a static simulator can be valid in such a critical situation.The key finding of the study states that there is no driving behavior validity in a static driving simulator for the tested dynamic scenario. The missing vestibular feedback causes a different behavior of the participants in field and simulator. The resulting absence of comparability leads to non-valid performance indicators. But these indicators are key parameters for analyzing the function and acceptance of active braking systems. So the question arises, which motion performance does a motion base have to provide in order to achieve valid acceleration simulation of such a highly dynamic collision avoidance scenario. The DS’s performance is measured in workspace, velocity and acceleration.     

Social representations associated with men and women drivers among French adolescents and adults. Effects of the perceiver’s age,sex, and socioeconomic status

The aim of this study was to investigate the specific contents of the social representations (SR) associated with men and women drivers and examine the effects of the social insertions of individuals (i.e., age, sex and socio-economic status) on the content and structure of these SR. A preliminary study with 414 French participants identified thematic content associated with men and women drivers using the verbal association method. Based on these themes, 833 French participants, equally distributed by age group (from 12 to 50 years-old and over), sex and socioeconomic status (SES), were asked to answer a questionnaire on men (N = 422) or women (N = 411) drivers. The results show that each of these SR is organized around three factors: incompetence, prudence and lack of self-control for women drivers; carelessness, skills and self-control for men drivers. In-group favoritism bias can be noted in both groups as male participants, more than female ones, rated men drivers as having self-control and women drivers as lacking self-control, whereas female participants, more than male ones, perceived men drivers as careless and women drivers as prudent. Despite this phenomenon, more male respondents than female ones in all age groups seemed to believe that women are not competent at driving, whereas both sexes seem to agree that men have good driving skills. Among most age groups, three characteristics associated with men drivers (confidence, speed and pleasure of driving) and four characteristics associated with female drivers (caution, civil, compliance with rules and vigilance) emerged as central in the SR. The SR associated with men drivers appeared to be stable and shared across age groups, whereas the SR associated with women drivers appeared more mixed, heterogeneous and unstable with age. Female participants with higher SES consider women drivers as more incompetent, less prudent and more lacking self-control than female participants with lower SES.     

Measuring information demand of a dynamic in-vehicle display while driving – A study evaluating the MARS (Masking Action Relevant Stimuli) method

The MARS (Masking Action Relevant Stimuli) method assesses information demand for dynamic stimuli while driving. An action relevant stimulus is masked and the driver presses a button to unmask the stimulus for a limited period. We interpreted button presses as information demand. Following our previous research (Rittger, Kiesel, Schmidt, & Maag, 2014), the current study further evaluates the method. We applied the MARS method to a dynamic in-vehicle display containing recommendations from a traffic light assistant. In a driving simulator, drivers approached intersections with different traffic light phasing. The display either presented simple or complex information. In half of the drives, the participants used the MARS method. The study had a full within subjects design and fixations were recorded in all conditions. The results showed that the information demand varied according to the information in the display and the traffic light phase. A comparison of button presses with fixations showed that one unmasking interval came along with one fixation on the display. As a conclusion, the MARS method can distinguish between conditions with high and low information demand for the display. Button presses relate to fixations on the display. Hence, the MARS method is a promising tool to assess the information demand in dynamic environments and can be applied as an extension or alternative for eye tracking.     

Modifying driver behaviour with passenger feedback

A feedback programme was employed to help drivers improve their safety behaviour based on the idea that particular types of driver error result from contingency traps as defined by Fuller [Journal of Applied Behaviour Analysis, 24 (1991) 73]. Two drivers and their single respective passengers participated. For each driver, repeated in-car observations were made of four unsafe driving behaviours. Two of these were sequentially targeted in the behavioural intervention that involved the passengers providing informational feedback to their driver. Both drivers showed a marked improvement across the targeted behaviours. The study demonstrated the applicability of behaviour analysis to the traffic domain and the efficacy of individual feedback as a behavioural tool for positive behaviour modification.