Showing papers in "Transportation Research Part F-traffic Psychology and Behaviour in 2015"

Public opinion on automated driving: results of an international questionnaire among 5000 respondents

Abstract: This study investigated user acceptance, concerns, and willingness to buy partially, highly, and fully automated vehicles. By means of a 63-question Internet-based survey, we collected 5000 responses from 109 countries (40 countries with at least 25 respondents). We determined cross-national differences, and assessed correlations with personal variables, such as age, gender, and personality traits as measured with a short version of the Big Five Inventory. Results showed that respondents, on average, found manual driving the most enjoyable mode of driving. Responses were diverse: 22% of the respondents did not want to pay more than $0 for a fully automated driving system, whereas 5% indicated they would be willing to pay more than $30,000, and 33% indicated that fully automated driving would be highly enjoyable. 69% of respondents estimated that fully automated driving will reach a 50% market share between now and 2050. Respondents were found to be most concerned about software hacking/misuse, and were also concerned about legal issues and safety. Respondents scoring higher on neuroticism were slightly less comfortable about data transmitting, whereas respondents scoring higher on agreeableness were slightly more comfortable with this. Respondents from more developed countries (in terms of lower accident statistics, higher education, and higher income) were less comfortable with their vehicle transmitting data, with cross-national correlations between ρ = −0.80 and ρ = −0.90. The present results indicate the major areas of promise and concern among the international public, and could be useful for vehicle developers and other stakeholders.

Analysing cycling as a social practice: An empirical grounding for behaviour change

Abstract: Despite significant national and local efforts over the last decade to stimulate uptake of cycling in the UK, levels of cycling (particularly utility cycling) remain at around 2% of journeys. Understanding of cycling behaviour and subsequent development of interventions has typically been undertaken using an individualist approach, often relying on psychologically based models of behaviour. This paper argues that Social Practice Theory (SPT) may be a valuable addition to practitioner’s toolboxes by providing an alternative means of understanding the complex dynamics between the elements that constitute the practice of utility cycling, allowing it to be considered as a social issue, rather than focusing solely on individual behaviour. This is demonstrated within the paper by the use of SPT to reanalyse quantitative and qualitative datasets that explore views and experiences of both cyclists and non-cyclists. Therein, the practice of utility cycling is described according to its three elements; materials, meaning and competences and the potential benefits of this approach are discussed; particularly its ideological shift away from ‘victim blaming’ and its natural support of interdisciplinary intervention design.

A review of definitions of fatigue - and a step towards a whole definition

Abstract: Despite its importance to health and safety, there is a long history of disagreement about how to operationalize fatigue when studying exertion in human transport operators. The current article reviews existing definitions, and consequently proposes a new definition as a step forward. A consideration of everyday use of the term finds that people often seem to use fatigue to describe a sensation related to exertion. Formal definitions of fatigue can be divided into a few broad definitions, capturing experiential, physiological and performance aspects of the construct, and many narrow definitions, focusing only on one or two of these aspects. Most existing definitions do not account explicitly for the role of sleep drives and sleepiness. They also fail to account for a wide range of factors associated with transport operator exertion, such as motivation and individual, organizational and environmental factors. Each of these points is assimilated in the derivation of a new “whole definition” of fatigue, in which the experience of human operator fatigue is a central aspect of the fatigue process. Although multidimensional and diffuse, the evolved definition does not detract from the measurement and study of limited aspects of fatigue. Rather, by describing the dynamic complexity of fatigue, it may help make explicit what different studies do or do not measure or account for in terms of the different aspects of fatigue. It is claimed that the proposed definition could be used to help harmonise attempts to study and tackle fatigue in transport health and safety contexts.

Learning and development of trust, acceptance and the mental model of ACC. A longitudinal on-road study

Abstract: To harness the potential of advanced driver assistance systems, drivers must learn how to use them in a safe and appropriate manner. The present study investigates the learning process, as well as the development of trust, acceptance and the mental model for interacting with adaptive cruise control (ACC). Research questions aim to model the learning process in mathematical/statistical terms, examine moments and conditions when these processes stabilize, and assess how experience changes the mental model of the system. A sample of fifteen drivers without ACC experience drove a test vehicle with ACC ten consecutive times on the same route within a 2-month period. All participants were fully trained in ACC functionality by reading the owner’s manual in the beginning. Results show that learning, as well as the development of acceptance and trust in ACC follows the power law of learning. All processes stabilize at a relatively high level after the fifth session, which corresponds to 185 km or 3.5 h of driving. No decline is observable with ongoing system experience. However, limitations that are not experienced tend to disappear from the mental model if they are not activated by experience. Therefore, it is recommended that users be periodically reminded of system limitations (e.g. by intelligent tutoring systems) to make sure that corresponding knowledge nodes are activated.

Am stressed, must travel: The relationship between mode choice and commuting stress

Abstract: The stress of commuting has serious public health and social implications. By comparing stress across different modes it is possible to determine which modes are more heavily contributing to this potential health and social issue. This study uses a large-scale university travel survey to compare commuter stress across three modes of transportation (walking, driving, and using public transit). It also investigates the specific factors that contribute to stress using these modes. Using ordered logistic regressions, the study develops a general model of stress and three mode-specific models. Results show that driving is the most stressful mode of transportation when compared to others. We also find that stressors for some modes are not stressors for others. Knowing which specific factors make certain modes stressful will help transportation and public health professionals make commuting a safer, more enjoyable, and less stressful activity; in turn this could mitigate the potentially serious health outcomes of a stressful commute.

A validation study of driving errors using a driving simulator

Abstract: BACKGROUND Driving simulators have become an important research tool in road safety. They provide a safer environment to test driving performance and have the capacity to manipulate and control situations that are not possible on-road. Aim To validate a laboratory-based driving simulator in measuring on-road driving performance by type and mean driving errors. METHODS Participants were instructed to drive a selected route on-road. The same route was programmed in the driving simulator using the UC/Win-road software. All participants completed a background questionnaire. On-road driving behaviours of participants and driving behaviours in the simulator were assessed by an occupational therapist and two trained researchers using an assessment form. Interclass correlations were calculated to assess the inter-rater agreement between the researchers on driving behaviours. Paired t-tests were used to assess differences in driving performance between the simulator and on-road assessments. RESULTS A convenience sample of 47 drivers aged 18-69 years who held a current Western Australian class C licence (passenger vehicle) were recruited into the study. The mean age was 34.80 years (SD: 13.21) with twenty-six males (55.32%) and 21 females (44.68%) completing the study. There was no statistical difference between the on-road assessment and the driving simulator for mirror checking, left, right and forward observations, speed at intersections, maintaining speed, obeying traffic lights and stop signs. CONCLUSION The preliminary results provide early support for the relative validity of the driving simulator which may be used for a variety of road safety outcomes with reduced risk of harm to participants.

Modelling pedestrian crossing behaviour in urban roads: a latent variable approach

Abstract: As pedestrians are the most exposed and vulnerable road users to traffic accidents, urban planners frequently propose alternatives to improve their safety. However, some solutions, such as pedestrian bridges and crosswalks at signalized intersections, usually imply longer walking distances compared to the direct crossing alternative which, in its turn, involves a higher risk. In this article, a hybrid framework is proposed to analyse the pedestrians' choice on how to cross an urban road where three crossing options are available: crossing directly, crossing by using a pedestrian bridge or using a crosswalk at a signalized intersection. The decision process is modelled as a discrete choice model incorporating latent variables to consider perceptions and psychological factors, using stated preference data coming from a survey applied in Bogota, Colombia. RESULTS show that the latent variables security/safety and attractiveness of each crossing alternative are relevant to understand the pedestrian crossing behaviour. These latent variables are strongly determined by socioeconomic characteristics of the individual (age, gender, level of study) and conditioned by the circumstances of the trip (main mode of transport, walking or not with children). It was found that a longer walking distance to a pedestrian bridge or a signalized crosswalk increases the probability of direct crossing, having a more relevant effect in the case of the pedestrian bridge.

Are we there yet? Trip duration and mood during travel

Abstract: Are longer trips more strenuous or unpleasant than shorter ones? This paper examines this question using data from the American Time Use Survey’s well-being module, which queried individuals about the extent to which they felt happiness, pain, sadness, stress, and fatigue during three randomly selected daily activities. Over 22,000 instances of individuals traveling are observed, including their trip duration, mode, purpose, and demographic and geographic information. Each emotion, plus a constructed, composite mood variable, is regressed on trip duration. Overall, the relationship between trip duration and traveler mood is not strong, which is unsurprising given prior findings on the limited impact of activities on mood. However, there is a statistically significant and negative association between trip duration and mood, primarily because of rising stress, fatigue and sadness on long trips. This is particularly true for drivers, while negative emotions do not rise with increasing trip duration for auto passengers. This suggests strain rises as the result of operating the vehicle for long periods, not traveling in an auto per se. Long bicycle trips are more painful than shorter ones, probably due to the physical demands of the mode, and long train trips are associated with less sadness. For commutes, long trips significantly degrade the mood of both drivers and bus riders, in the latter case probably due in part to vehicle crowding and standing. The findings imply that reducing the duration of trips, for example through land use policies that reduce trip distances, or congestion reduction, would have emotional benefits. Policies to promote ridesharing instead of solo driving for long trips may increase traveler mood in the aggregate. Improving bus service or substituting rail for bus for long commute trips may also improve traveler mood.

Cycle commuting intention: A model based on theory of planned behaviour and social identity

Abstract: Although cycling as a mode of transport can provide various important benefits to cities and their transport systems, it accounts for only a small proportion of commuter trips in southern Europe. The aim of this study was to develop a new model based on Ajzen’s (1991) theory of planned behaviour (TPB), but including social identity as an additional predictor variable to improve the explanatory capability of the TPB. We conducted a telephone survey of a representative sample of 595 non-cycle commuters in the Spanish city of Vitoria-Gasteiz, which has a moderate proportion of bicycle users (6.9%). Confirmatory factor analysis to test the model showed satisfactory overall measurement fit, and all sub-scales had high reliability and validity coefficients. The findings demonstrated the value of incorporating social identity into the TPB to capture motivational factors relevant to cycle commuting. The relationships between the factors in the model indicated that there is a strong link between identifying as ‘a cyclist’ and perceived self-efficacy with respect to cycling. Furthermore, the results suggest that a more specific measure of perceived self-efficacy, targeting concrete behaviours could be used to inform development of initiatives to promote urban cycling. Our data also revealed that, excluding control variables such as journey time, economic cost and distance, the psychosocial variables included in the model predicted 32% of the variance in car users’ intention to start commuting by bicycle.

A qualitative study on the role of the built environment for short walking trips

Abstract: The present study uses a qualitative approach with the aim to identify built environmental factors influencing short walking distances for transportation among adults (18–65 years), with special attention to micro-scale attributes. Three focus groups were held in Valencia (Spain) and conducted with participants who undertook, at least once a week, one short non-shopping trip in any travel mode (were “short trip” is defined as less than 30–45 min walking distance). A thematic analysis of the data was performed and six categories of factors emerged related to the built environment. Factors were also classified as either barriers to walking, or secondary factors related to the attractiveness of the walking experience and the pedestrian route choice. Results show that factors related to safety from crime are the most deterrent to walking (absence of people and poor street lighting), along with the availability of car parking at destination for car users. Crossing large avenues and roundabouts in Valencia can be a deterrent to walking because of the high density of pedestrian traffic signals with a poor coordination, leading to long crossing waiting times. Secondary factors such as wide sidewalks, the presence of trees, and low traffic volume roads were mentioned by almost all participants. Our findings suggest that sidewalk width may not only influence pedestrian route choice but can be a barrier to walking. Focus groups also revealed that sidewalk cafes and bollards were seen as physical obstacles by some participants.

How satisfying is the Scale for Travel Satisfaction

Abstract: The Satisfaction with Travel Scale (STS) has recently been developed to measure people’s satisfaction with travel. It supposedly consists of two affective and one cognitive dimension. As there have only been a few tests of its reliability and structure to date, this paper reports new tests using data on leisure trips from Ghent (Belgium). Differences in the reliability and structure of the STS by transport mode – car, public transport, bicycling and walking – are also considered. Overall, the results suggest that the specification of a single underlying dimension for affect rather than two offers a superior fit to the Ghent data, both for all modes combined and for car use and cycling separately. For public transport and walking a three-dimensional structure is more appropriate although individuals items do not load on the two affective dimensions as expected. Differences between previous studies and ours are partly caused by differences in how two of the scale’s items – alert/tired and confident/worried – are correlated with the other items. Future studies using the STS may want to adapt the structure of STS by omitting some items or replacing them with alternatives as this may reduce respondent burden and increase internal consistency of the STS.

The estimation of vehicle speed and stopping distance by pedestrians crossing streets in a naturalistic traffic environment

Abstract: The ability to estimate vehicle speed and stopping distance accurately is important for pedestrians to make safe road crossing decisions. In this study, a field experiment in a naturalistic traffic environment was conducted to measure pedestrians' estimation of vehicle speed and stopping distance when they are crossing streets. Forty-four participants (18-45 years old) reported their estimation on 1043 vehicles, and the corresponding actual vehicle speed and stopping distance were recorded. In the speed estimation task, pedestrians' performances change in different actual speed levels and different weather conditions. In sunny conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 40 km/h but were able to accurately estimate speeds that were lower than 40 km/h. In rainy conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 45 km/h but were able to accurately estimate speeds ranging from 35 km/h to 45 km/h. In stopping distance estimation task, the accurate estimation interval ranged from 60 km/h to 65 km/h, and pedestrians generally underestimated the stopping distance when vehicles were travelling over 65 km/h. The results show that pedestrians have accurate estimation intervals that vary by weather conditions. When the speed of the oncoming vehicle exceeded the upper bound of the accurate interval, pedestrians were more likely to underestimate the vehicle speed, increasing their risk of incorrectly deciding to cross when it is not safe to do so. (C) 2015 Elsevier Ltd. All rights reserved.

The effect of age, gender and roadway environment on the acceptance and effectiveness of Advanced Driver Assistance Systems

Abstract: The purpose of this paper was to investigate the effect of age, gender and roadway environment on the acceptance as well as effectiveness of the Advanced Driver Assistance Systems (ADAS). Better understanding on the age and gender differences in technology acceptance and effectiveness toward the ADAS on various roadways could help encourage drivers’ use of new technology for safe driving. In this study, 52 drivers participated in on-road field experiments with or without the ADAS providing a forward collision warning and a lane departure warning. Each participant drove approximately 5.5 km of rural road (about 10 min), 6.2 km of urban road (about 25 min) and 9.6 km of highway (about 10 min). Upon completion of these driving sessions, the ADAS-supported group participants (half of all participants) responded to questionnaire. Field experiment results showed that there were significant age and gender differences in the acceptance and effectiveness of the ADAS and the roadway environment affected the effectiveness of the ADAS. Findings from this study indicated that it is essential to assess age and gender differences in effectiveness and acceptance of new in-vehicle technology for avoiding unexpected negative effects on a certain age and gender segment.

Racial bias in driver yielding behavior at crosswalks

Abstract: Psychological and social identity-related factors have been shown to influence drivers' behaviors toward pedestrians, but no previous studies have examined the potential for drivers' racial bias to impact yielding behavior with pedestrians. If drivers' yielding behavior results in differential behavior toward Black and White pedestrians, this may lead to disparate pedestrian crossing experiences based on race and potentially contribute to disproportionate safety outcomes for minorities. We tested the hypothesis that drivers' yielding behavior is influenced by pedestrians' race in a controlled field experiment at an unsignalized midblock marked crosswalk in downtown Portland, Oregon. Six trained male research team participants (3 White, 3 Black) simulated an individual pedestrian crossing, while trained observers cataloged the number of cars that passed and the time until a driver yielded. RESULTS (88 pedestrian trials, 173 driver-subjects) revealed that Black pedestrians were passed by twice as many cars and experienced wait times that were 32% longer than White pedestrians. RESULTS support the hypothesis that minority pedestrians experience discriminatory treatment by drivers at crosswalks.

Controllability of partially automated driving functions - does it matter whether drivers are allowed to take their hands off the steering wheel?

Abstract: Different motor vehicle manufacturers have recently introduced assistance systems that are capable of both longitudinal and lateral vehicle control, while the driver still has to be able to take over the vehicle control at all times (so-called Partial Automation). While these systems usually allow hands-free driving only for short time periods (e.g., 10 s), there has been little research whether allowing longer time periods of hands-off driving actually has a negative impact on driving safety in situations that the automation cannot handle alone. Altogether, two partially automated assistance systems, differing in the permitted hands-off intervals (Hands-off system vs. Hands-on system, n = 20 participants per assistance condition, age 25–70 years) were implemented in the driving simulation with a realistic take-over concept. The Hands-off system is defined by having a permitted hands-off interval of 120 s, while the Hands-on system is defined by a permitted hands-off interval of 10 s. Drivers’ reactions at a functional system limit were tested under conditions of high ecological validity: while driving in a traffic jam, participants unexpectedly encountered a time-critical situation, consisting of a vehicle at standstill that appeared suddenly and required immediate action. A visual-auditory take-over request was issued to the drivers. Regardless of the hands-off interval, all participants brought the vehicle to a safe stop. In spite of a stronger brake reaction with the Hands-on system, no significant differences between assistance levels were found in brake reaction times and the criticality of the situation. The reason for this may be that most of the drivers kept contact with the steering wheel, even in the Hands-off condition. Neither age nor prior experience with ACC was found to impact the results. The study thus demonstrates that permitting longer periods of hands-off driving does not necessarily lead to performance deficits of the driver in the case of take-over situations, if a comprehensive take-over concept is implemented.

Risky driving among young male drivers: The effects of mood and passengers

Abstract: Young male drivers are at greater risk of automobile crashes than other drivers. Efforts to reduce risky driving in this population have met with mixed success. The present research was designed to examine the effects of induced mood and the presence or absence of passengers on risky driving in young male drivers. Male drivers (n = 204) aged 16–18 were tested in a driving simulator. This study employed a 2 (happy/sad mood) by 2 (passenger present/absent) between-subjects factorial design, and examined driving behavior in a simulator. Measures of risky driving were combined into two factors representing speed (e.g., exceeding the speed limit) and carelessness (e.g., crossing the center line). Findings indicated that driving with a passenger resulted in faster driving than driving alone. Although there was no significant main effect of induced mood on driving, results revealed a significant interaction of mood and passenger conditions: when in a happy mood, driving with a passenger significantly increased driving speed. There were no significant effects of passenger or mood on careless driving. In conclusion, both mood and passenger presence are important factors in fast driving among young male drivers. Results are discussed in the context of developing more effective countermeasures for this at-risk population.

Testing extrinsic and intrinsic motivation as explanatory variables for the safety climate-safety performance relationship among long-haul truck drivers

Abstract: The paper tests the proposition that the organizational climate-behavior relationship is based primarily on extrinsic motivation induced by climate perceptions. Using safety climate as exemplar, the effect of climate-induced extrinsic motivation was compared with that of engagement-induced intrinsic motivation on safety behavior and subsequent injury outcomes. Using a sample of long-haul truck drivers representing lone employees, (individual-level) safety climate perceptions and employee engagement predicted safety behavior, which mediated their effect on subsequently measured road injury outcomes. Consistent with meta-analytic evidence suggesting a non-symmetric compensatory relationship between extrinsic and intrinsic motivation, high safety climate undermined the effect of engagement on safety behavior with the reverse being true under low safety climate. This resulted in a moderation effect of engagement on the strength of relationship between climate perceptions and safety behavior. Theoretical and practical implications for climate, engagement, and lone work research are discussed.

How does glance behavior influence crash and injury risk? A ‘what-if’ counterfactual simulation using crashes and near-crashes from SHRP2

Abstract: As naturalistic driving data become increasingly available, new analyses are revealing the significance of drivers’ glance behavior in traffic crashes. Due to the rarity of crashes, even in the largest naturalistic datasets, near-crashes are often included in the analyses and used as surrogates for crashes. However, to date we lack a method to assess the extent to which driver glance behavior influences crash and injury risk across both crashes and near-crashes. This paper presents a novel method for estimating crash and injury risk from off-road glance behavior for crashes and near-crashes alike; this method can also be used to evaluate the safety impact of secondary tasks (such as tuning the radio). We apply a ‘what-if’ (counterfactual) simulation to 37 lead-vehicle crashes and 186 lead-vehicle near-crashes from lead-vehicle scenarios identified in the SHRP2 naturalistic driving data. The simulation combines the kinematics of the two conflicting vehicles with a model of driver glance behavior to estimate two probabilities: (1) that each event becomes a crash, and (2) that each event causes a specific level of injury. The usefulness of the method is demonstrated by comparing the crash and injury risk of normal driving with the risks of driving while performing one of three secondary tasks: the Rockwell radio-tuning task and two hypothetical tasks. Alternative applications of the method and its metrics are also discussed. The method presented in this paper can guide the design of safer driver–vehicle interfaces by showing the best tradeoff between the percent of glances that are on-road, the distribution of off-road glances, and the total task time for different tasks.

Neighbourhood preferences, active travel behaviour, and built environment: an exploratory study

Abstract: In the current study we investigated the extent to which neighbourhood preferences could be used as a base to group people in order to explore their residential and travel choices. The basic idea of this study was that the preferences people would have for their residential and travel choices might be a robust predictor of their actual travel behaviour, and that the neighbourhood preferences might distinguish people in terms of the characteristics of their living environment. We used a moderation model to test whether the effect of built environment on travel behaviour varied in terms of resident's type. A total of 3403 inhabitants of the city of Tampere in Finland participated in the study. A web-based public participation GIS survey combining the questionnaires with a map (SoftGIS technique) was used to collect the data. We identified two distinct groups of residents in terms of general neighbourhood preferences. The findings showed that clustering residents based on neighbourhood preferences moderated the association between some features of density measures and travel behaviour. We found significant differences between the two clusters in both the frequencies and the distance of pedestrian and bike travel. The findings revealed that inhabitants of neighbourhoods with a larger percentage of green surroundings had a greater perception of neighbourhood stability than did the residents of neighbourhoods with a smaller percentage of green surroundings.

Assessing driver acceptance of Intelligent Transport Systems in the context of railway level crossings

Abstract: Intelligent Transport Systems (ITS) have the potential to substantially reduce the number of crashes caused by human errors at railway levels crossings. Such systems, however, will only exert an influence on driving behaviour if they are accepted by the driver. This study aimed at assessing driver acceptance of different ITS interventions designed to enhance driver behaviour at railway crossings. Fifty eight participants, divided into three groups, took part in a driving simulator study in which three ITS devices were tested: an in-vehicle visual ITS, an in-vehicle audio ITS, and an on-road valet system. Driver acceptance of each ITS intervention was assessed in a questionnaire guided by the Technology Acceptance Model and the Theory of Planned Behaviour. Overall, results indicated that the strongest intentions to use the ITS devices belonged to participants exposed to the road-based valet system at passive crossings. The utility of both models in explaining drivers’ intention to use the systems is discussed, with results showing greater support for the Theory of Planned Behaviour. Directions for future studies, along with strategies that target attitudes and subjective norms to increase drivers’ behavioural intentions, are also discussed.

Towards testing auditory–vocal interfaces and detecting distraction while driving: A comparison of eye-movement measures in the assessment of cognitive workload

Abstract: Recently, there has been a growing need among researchers to understand the problem of cognitive workload induced by auditory-verbal-vocal tasks while driving in realistic conditions. This is due to the fact that we need (a) valid methods to evaluate in-vehicle electronic devices using voice control systems and (b) experimental data to build more reliable driver state monitoring systems. In this study, we examined the effects of cognitive workload induced by the delayed digit recall task (n-back) while driving. We used a high-fidelity driving simulator and a highway scenario with moderate traffic to study eye movements in realistic driving conditions. This study included 46 participants, and the results indicate that a change in pupil size is most sensitive for measuring changes in cognitive demand in auditory-verbal-vocal tasks. Less sensitive measures included changes in fixation location and blink rate. Fixation durations and the driving performance metrics did not provide sensitive measures of graded levels of cognitive demand. Keywords: Driver distraction;

Anger, aggression and road rage behaviour in Malaysian drivers

Abstract: This study tested the four factor structure of the Driving Anger Expression Inventory (DAX) in a sample of young Malaysian drivers and the relationship these factors had with several other variables. Confirmatory Factor Analysis broadly supported the four factor solution of the DAX, being: Personal Physical Aggressive Expression, Use of a Vehicle to Express Anger, Verbal Aggressive Expression and Adaptive/Constructive expression. The short version of the Driving Anger Scale was positively correlated with the three types of aggressive responses and not surprisingly with a variable comprised of all three types of aggressive responses (Total Aggressive Expression). Total Aggressive Expression was higher for males and negatively related to age, years licensed and slower preferred driving speed. All three of the aggressive forms of expression had significant relationships with crash-related conditions, such as: loss of concentration, losing control of their vehicle, having received a ticket and involvement in near-misses. In particular, all three of the aggressive forms of expression had significant relationships with losing control of the vehicle and Total Aggressive Expression was correlated with all crash-related conditions. In addition, Personal Physical Aggressive Expression and Total Aggressive Expression were both significantly related to crash involvement.

Behavioural analysis of interactions between pedestrians and vehicles in street designs with elements of shared space

Abstract: This paper describes the development and implementation of qualitative behavioural criteria in order to analyse the conduct of pedestrians and vehicles when they are required to interact with each other, with particular interest to street designs with elements of shared space. The new behavioural analysis technique is developed by identifying the fundamental principles that underpin existing traffic analyses, such as traffic conflicts techniques, and adapting those to a qualitative framework that describes the mindset and rationale of road users. The technique is then applied to a case study in London, using video data from periods before and after the redevelopment of the Exhibition Road site from a conventional dual carriageway to a modern design with some elements of shared space. With the main goals being to assess the pedestrians’ confidence and the vehicles’ tolerance/patience when forced to interact with each other, behavioural trends are related to instantaneous characteristics of the vehicle flow (vehicle approach speed and traffic density). The data produced are used to develop and validate qualitative behavioural relationships for pedestrian–vehicle interactions, as well as location-specific conclusions for the Exhibition Road site.

Predicting aberrant driving behaviour: the role of executive function

Abstract: The aim of the current study was to assess the relevance of three components of executive function: working memory, sustained attention and behavioural inhibition for explaining aberrant driving behaviour, driving errors, driving violations and crashes. A total of 107 participants (M age = 30.2; 62% male) with a valid driving license participated in the study. A battery of cognitive assessments were administered, including the Wechsler Digit Span Backward task, Continuous Performance Task (CPT), Go/No-go task, and the Driving Behaviour Questionnaire (DBQ). RESULTS indicated that aberrant driving behaviour and driving errors were significantly correlated to sustained attention and behavioural inhibition. Driving violations related to behavioural inhibition. Regression indicated that behavioural inhibition significantly predicted aberrant driving behaviour, driving errors and driving violations. Gender predicted driving violations and driving errors. Number of reported crashes during the last year was related to driving errors, behavioural inhibition and driving violations. In conclusion, inhibitory control related to different aspects of driving indicating that impulsivity may underlie various aberrant driving behaviour and crashes. It is discussed that poor inhibitory control could result in aberrant driving behaviour causing conflict and leading to crashes.

Psychological predictors of eco-driving: a longitudinal study

Abstract: Eco-driving has well-known positive effects on fuel economy and greenhouse-gas emissions. Moreover, eco-driving reduces road-traffic noise, which is a serious threat to the health and well-being of many people. We investigated the psychological predictors of the adoption of eco-driving from the perspective of road-traffic noise abatement. The data came from 890 car drivers who participated in a longitudinal survey over four months. Specifically, we tested the effects of the intention to prevent road-traffic noise, variables derived from the theory of planned behavior (social norm, perceived behavioral control, and attitude), and variables derived from the health action process approach (implementation intention, maintenance self-efficacy, and action control) on the intention to practice eco-driving and on eco-driving behavior. The intention to prevent road-traffic noise was not linked to the intention to practice eco-driving. The strongest predictors of the intention to practice eco-driving were attitude and perceived behavioral control. The strongest predictor of eco-driving behavior was action control. The link between behavioral intention and behavior was weak, indicating that drivers have difficulties putting their intention to practice eco-driving into action. Therefore, intervention efforts should directly address and support the transition from intention to behavior. This could be accomplished by providing reminders, which help to maintain behavioral intention, and by providing behavior feedback, which helps car drivers to monitor their behavior.

Frequency and impact of hands-free telephoning while driving - results from naturalistic driving data

Abstract: The frequency and impact of hands-free telephoning while driving was analyzed based on naturalistic driving data from 106 drivers. The results from naturalistic driving data were compared with the results from experimental approaches. The implication of the overall results and the differences across drivers are discussed. Continuous information on the usage of the hands-free phone equipment was available which made it possible to include the entire database (∼1 000 000 km) in a completely automatized analysis. RESULTS show that drivers talked on a hands-free phone about 11% of driving time. There were large differences across drivers in the frequency and usage of a hands-free phone. While telephoning, an adaptation of driving behavior could be found. Drivers slowed down and increased their distance to the lead vehicle. Furthermore, during telephoning, an overall reduction of potentially critical driving situations was found. Overall, the results indicate that compensation for telephoning was carried out with a long-term change of driving behavior, rather than with a short term adaption to the situation. Keywords: Driver distraction;

Allocation of visual attention while driving with simulated augmented reality

Abstract: Augmented reality (AR) technologies aim to optimize the visual attention of the driver by increasing the salience of high value elements. In such systems, 'value' is typically seen as linked to the general activity of driving, but not manoeuvres. However, several studies have shown that during activity, eye movements are specific to the immediate goal. In our experiment, 48 participants watched videos of automobile driving situations, during which they had to make decisions. In these videos, some situational cues were graphically highlighted. Depending on the experimental group, highlighted cues related to either the general driving task (e.g. road signs, pedestrians) or to a specific manoeuvre (e.g. look for overtaking cars before changing the lane). The results show that AR impacts the allocation of visual attention more strongly during the decision-making phase. In all AR conditions, the ability to extract information is less efficient. In particular, highlighting (by AR) general cues does not affect the detection of cues related to a manoeuvre, but it does change the allocation of visual attention: fixations are more numerous and less task-specific.

The perspectives of older drivers on the impact of feedback on their driving behaviours: A qualitative study

Abstract: Self-regulation is a coping strategy that allows older drivers to drive safely for longer Self-regulation depends largely on the ability of drivers to evaluate their own driving Therefore the success of self-regulation, in terms of driving safety, is influenced by the ability of older drivers to have insight into their declining driving performance In addition, previous studies suggest that providing feedback to older adults regarding their driving skills may lead them to change their driving behaviour However, little is currently known about the impact of feedback on older drivers’ self-awareness and their subsequent driving regulatory behaviour This study explored the process of self-regulation and driving cessation among older drivers using the PAPM as a framework It also investigated older adults’ perceptions and opinions about receiving feedback in regards to their driving abilities Qualitative focus groups with 27 participants aged 70 years or more were conducted Thematic analysis resulted in the development of five main themes; the meaning of driving, changes in driving pattern, feedback, the planning process, and solutions The analysis also resulted in an initial model of driving self-regulation among older drivers that is informed by the current research and the Precaution Adoption Process Model as the theoretical framework It identifies a number of social, personal, and environmental factors that can either facilitate or hinder people’s transition between stages of change The findings from this study suggest that further elaboration of the PAPM is needed to take into account the role of insight and feedback on the process of self-regulation among older drivers

Traffic Accidents Triggered by Drivers at Work – A Survey and Analysis of Contributing Factors

Abstract: This report outlines the results of a study of severe road traffic accidents in Norway, triggered by drivers at work. The aim has been to examine whether and to what extent risk factors of these triggering drivers and their vehicles can be traced back to work-related factors. The study is based on data from the Accident Analysis Groups (AAG) of the Norwegian Public Roads Administration (NPRA), reports from The Transport Accident Investigation Board Norway (AIBN) and interviews with nine experts. The quantitative analysis of AAG data shows that too high speed for the circumstances, failure to use seat belt and insufficient information gathering were the most important risk factors in fatal accidents triggered by drivers at work. The qualitative analysis of reports from AIBN and expert interviews uncovered the following work-related factors considered central for traffic safety: follow up of drivers’ speed, driving style and use of seat belt, pay systems, safety culture, risk assessments, procedures/work descriptions and training. The AIBN reports and the interviews indicate that the following framework conditions influence traffic safety: time pressure, competition, type of transport, accident investigations/inspections. The majority of the interviewees held that work-related factors with potential implications for traffic safety are insufficiently monitored in controls and inspections.

Cross-generational acceptance of and interest in advanced vehicle technologies: A nationwide survey

Abstract: The number of older drivers on the roadways is increasing; at the same time, technology in the automotive environment is rapidly evolving. To investigate the potential impact of these converging changes, this study used a cross-generational approach to compare driver attitudes toward advanced automotive technologies. Approximately 1000 drivers between the ages of 18 and 85 located across the United States responded to a survey about their opinions regarding general technology, advanced in-vehicle technology, and near-horizon connected vehicle systems. Participant responses were categorized using a generational construct, sorting responses not only by age but by shared life experiences (e.g. economic circumstances, involvement in wartime activities, cultural movements, etc.). The oldest generation (the “Silent” generation) exhibited the least interest in and comfort with advanced technology, although they owned and used advanced in-vehicle technology at approximately the same rates as the two middle generations. The youngest generation (the “Millennial” generation) was most likely to be interested in and comfortable with technology, but was least likely to own vehicles with advanced technology. All participants expressed interest in safety-related connected vehicle systems, but less so in infotainment applications. Reservations regarding data security and system cost were shared across generations. These findings are framed in the context of an aging population with unique driving and vehicle needs, and provide information that may assist both with vehicle technology design aspects and the proposed large-scale implementation of connected vehicle systems, including considerations for seniors and emphasis on safety systems and data security.