Dick de Waard - Academia.edu (original) (raw)

Papers by Dick de Waard

Stress, Workload, and Fatigue

Frontiers in Psychology

Pedestrians are commonly engaged in other activities while walking. The current study assesses (1... more Pedestrians are commonly engaged in other activities while walking. The current study assesses (1) whether pedestrians are sufficiently aware of their surroundings to successfully negotiate obstacles in a city, and (2) whether various common walking practices affect awareness of obstacles and, or, avoidance behavior. To this end, an obstacle, i.e., a signboard was placed on a pavement in the city centre of Utrecht, the Netherlands. The behavioral measure consisted of the distance to the signboard before pedestrians moved to avoid it. After passing, participants were interviewed to obtain thought samples, self-reported route familiarity, a confirmation of secondary task engagement, and to assess awareness through recall and recognition of the signboard and its text. In this study 234 pedestrians participated. More than half of the participants (53.8%) was unaware of the signboard, still none of them had bumped into it. Mind wandering, being engaged in secondary tasks such as talking with a companion or using a mobile phone, and being familiar with a route, did not affect awareness nor avoidance behavior. In conclusion, despite being very common there was no evidence that walking without awareness necessarily results in risk. The absence of awareness does not imply any absence of cognitive and perceptual processing. Pedestrians are still capable of successfully avoiding obstacles in their path, even in visually more challenging environments such as a city centre. It is argued that this is because walking consists of highly automated, skilled behavior.

Disability and Rehabilitation

Purpose: This study aims to identify the most important factors that influence the independent bi... more Purpose: This study aims to identify the most important factors that influence the independent bicycle use of visually impaired people in the Netherlands. Materials and methods: Both visually impaired people and professionals participated in a two-round online Delphi study (n ¼ 42). In Round 1 the participants identified the factors which they ranked by relevance in Round 2. Results: The participants prioritised environmental factors related to the traffic situation, the characteristics of the infrastructure, and weather and light conditions (Kendall's W ¼ 0.66). They indicated that the most influencing personal factors are related to personality, traffic experience, and personal background (W ¼ 0.58). Glaucoma was ranked as the most relevant ophthalmic condition (W ¼ 0.74), while glare was regarded as the most important factor with respect to the visual functions (W ¼ 0.78). Conclusions: The factors provided by this study can be used to optimise the independent cycling mobility of visually impaired people. More research is needed to investigate, both, how and to what extent the mentioned factors influence the cycling behaviour. ä IMPLICATIONS FOR REHABILITATION The results of this study can be used to set priorities during the rehabilitation and training of visually impaired people who wish to cycle independently. Visually impaired cyclists may compensate for the consequences of their visual impairments by taking alternative routes that suit their individual abilities and limitations. Since gaining and maintaining self-confidence is important for independent cycling with a visual impairment, practitioners such as mobility trainers should not only focus on cycling-related skills and abilities, but also aim to improve the self-confidence of visually impaired people who wish to cycle.

Alzheimer disease and associated disorders

Dementia is a risk factor for unsafe driving. Therefore, an assessment strategy has recently been... more Dementia is a risk factor for unsafe driving. Therefore, an assessment strategy has recently been developed for the prediction of fitness to drive in patients with the Alzheimer disease (AD). The aim of this study was to investigate whether this strategy is also predictive of fitness to drive in patients with non-AD dementia, that is, vascular dementia, frontotemporal dementia, and dementia with Lewy bodies. Predictors were derived from 3 types of assessment: clinical interviews, neuropsychological tests, and driving simulator rides. The criterion was the pass-fail outcome of an official on-road driving assessment. About half of the patients with non-AD dementia (n=34) failed the on-road driving assessment. Neuropsychological assessment [area under the curve (AUC)=0.786] was significantly predictive of fitness to drive in patients with non-AD dementia, however, clinical interviews (AUC=0.559) and driving simulator rides (AUC=0.404) were not. The fitness-to-drive assessment strategy ...

Proceedings of the Human Factors and Ergonomics Society Annual Meeting

Ergonomics, 2017

Cycling with a classic paper map was compared with navigating with a moving map displayed on a sm... more Cycling with a classic paper map was compared with navigating with a moving map displayed on a smartphone, and with auditory, and visual turn-by-turn route guidance. Spatial skills were found to be related to navigation performance, however only when navigating from a paper or electronic map, not with turn-by-turn (instruction based) navigation. While navigating, 25% of the time cyclists fixated at the devices that present visual information. Navigating from a paper map required most mental effort and both young and older cyclists preferred electronic over paper map navigation. In particular a turn-by-turn dedicated guidance device was favoured. Visual maps are in particular useful for cyclists with higher spatial skills. Turn-by-turn information is used by all cyclists, and it is useful to make these directions available in all devices.

Traffic injury prevention, Feb 13, 2016

There is no consensus yet on how to determine which patients with cognitive impairment are able t... more There is no consensus yet on how to determine which patients with cognitive impairment are able to drive a car safely and which are not. Recently, a strategy was composed for the assessment of fitness to drive, consisting of clinical interviews, a neuropsychological assessment, and driving simulator rides, which was compared with the outcome of an expert evaluation of an on-road driving assessment. A selection of tests and parameters of the new approach revealed a predictive accuracy of 97.4% for the prediction of practical fitness to drive on an initial sample of patients with Alzheimer's dementia. The aim of the present study was to explore whether the selected variables would be equally predictive (i.e. valid) for a closely related group of patients, i.e. patients with Mild Cognitive Impairment (MCI). Eighteen patients with mild cognitive impairment completed the proposed approach to the measurement of fitness to drive, including clinical interviews, a neuropsychological asse...

Applied Ergonomics, Mar 1, 2009

Adaptive support has the potential to keep the operator optimally motivated, involved, and able t... more Adaptive support has the potential to keep the operator optimally motivated, involved, and able to perform a task. In order to use such support, the operator's state has to be determined from physiological parameters and task performance measures. In an environment where the task of an ambulance dispatcher was simulated, two studies have been carried out to evaluate the feasibility of using cardiovascular measures for adaptive support. During performance of this 2-3 h lasting planning task, a pattern of results is found that can be characterized by an initial increase of blood pressure and heart rate and a decrease of heart rate variability (defense reaction pattern) followed by an ongoing increase of blood pressure counteracted by a decrease in heart rate. This pattern can be explained by an augmented short-term blood pressure control (baroreflex), which is reflected in an increase of baroreflex sensitivity. Additionally, in this latter phase heart rate variability (HRV) increases as a function of time, while blood pressure variability decreases. In the two studies performed, the baroreflex pattern was consistent for all the relevant variables. In both studies there were periods with high and low workload. Effects of task load are mainly reflected in the variability measures, while in the second study, additionally, blood pressure level was higher during periods with high task demands. The conclusion of the studies is that consistent cardiovascular response patterns can be recognized during this semi-realistic planning task, where variability measures are most sensitive to task demand changes, while blood pressure and baroreflex sensitivity are most informative with respect to cardiovascular state changes. These findings can be seen as a great potential benefit for future use in adaptive support applications.

Accident Analysis and Prevention, May 1, 2010

Many traffic accidents are caused by, or at least related to, inadequate mental workload, when it... more Many traffic accidents are caused by, or at least related to, inadequate mental workload, when it is either too low (vigilance) or too high (stress). Creating variations in mental workload and accident-prone driving for research purposes is difficult in the real world. In driving simulators the measurement of driver mental workload is relatively easily conducted by means of physiological measures, although good research skills are required and it is time-consuming. The fact that modern driving simulator environments are laboratory-equivalent nowadays allows full control with respect to environmental conditions, scenarios and stimuli, and enables physiological measurement of parameters of mental workload such as heart rate and brain activity. Several examples are presented to illustrate the potential of modern highstandard driving simulator environments regarding the monitoring of drivers' mental workload during task performance.

... Rineke Richters dank ik voor de regelmatig geboden hulp bij het opsporen van literatuur. Natu... more ... Rineke Richters dank ik voor de regelmatig geboden hulp bij het opsporen van literatuur. Natuurlijk ben ik Corine erg veel dank verschuldigd voor al haar steun, en Jolien, omdat zij mij altijd vrolijk stemt. Page 8. Page 9. Table of contents ...

International Journal of Traffic and Transportation Engineering, 2014

Twenty-five drivers completed a ride in their own car over a standard motorway and through two ty... more Twenty-five drivers completed a ride in their own car over a standard motorway and through two types of road works, the standard Dutch road works design and an adapted format. The latter type included wider lanes, a higher posted speed limit and white instead of yellow delineation. During the rides video images of the road and the driver were made and stored together with GPS information. From these sources speed, lateral position, and number of hands on the steering wheel were scored. In addition, after passing each of the two road works and the control motorway section, the participants parked their car off the motorway and completed a questionnaire with questions about invested mental effort while driving over the section, and how they had experienced driving over that specific section. Results show that drivers more often considered the speed limit of the new road works to be appropriate than the speed limit of the current road works, and that the new type was more appreciated, and that compliance to the speed limit was better. Mental effort invested while driving through the road works was higher than while driving over the control road, but was similar while driving through the two types of road works, even if actual driving speed at the new road works was higher.

PloS one, 2016

The number of patients with Alzheimer's disease (AD) is increasing and so is the number of pa... more The number of patients with Alzheimer's disease (AD) is increasing and so is the number of patients driving a car. To enable patients to retain their mobility while at the same time not endangering public safety, each patient should be assessed for fitness to drive. The aim of this study is to develop a method to assess fitness to drive in a clinical setting, using three types of assessments, i.e. clinical interviews, neuropsychological assessment and driving simulator rides. The goals are (1) to determine for each type of assessment which combination of measures is most predictive for on-road driving performance, (2) to compare the predictive value of clinical interviews, neuropsychological assessment and driving simulator evaluation and (3) to determine which combination of these assessments provides the best prediction of fitness to drive. Eighty-one patients with AD and 45 healthy individuals participated. All participated in a clinical interview, and were administered a neu...

We are living in an ageing population. In the Netherlands for example, the share of people aged 6... more We are living in an ageing population. In the Netherlands for example, the share of people aged 65 and above will increase to about 20% in 2020. It is likely that the proportion of car drivers in this age category will increase in a similar way or even more. The Dutch government aims to facilitate this development by specifically looking at ways to support the older driver. There are indications that older drivers are more likely to get involved in an accident when entering the highway. In addition, older drivers tend to drive slowly on the acceleration lane. In other situations, e.g. when turning left, this is a good strategy because it increases available manoeuvring time, but in case of merging it is deemed wiser to match speed to the speed on the main lane. Therefore, we designed and selected variable message signs aimed at assisting speed choice. First, we invited a small group of older drivers for a focus session, thereby greatly reducing the number of designs to test. Second, the selected signs were implemented in a driving simulator and shown dynamically to older drivers and to drivers in a younger control group. Results indicate one clear winning design.

Phileas is a high quality public transport vehicle combining characteristics of bus, tram, and th... more Phileas is a high quality public transport vehicle combining characteristics of bus, tram, and the underground. Phileas is equipped with pneumatic tyres and complies with the statutory regulations for buses. Accordingly Phileas may drive everywhere on public roads where buses are allowed to drive. On dedicated lanes Phileas can also drive as a track vehicle and drive and stop automatically.

Journal of Neural Transmission, 2015

Take-down policy If you believe that this document breaches copyright please contact us providing... more Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Psychopharmacology, 2015

Comparing treatment effects of oral THC on simulated and on-the-road driving performance: testing... more Comparing treatment effects of oral THC on simulated and on-the-road driving performance: testing the validity of driving simulator drug research.

Cognition, Technology & Work, 2014

Transportation Research Part F: Traffic Psychology and Behaviour, 2010

It has been suggested that a driver"s hand position on the steering wheel can reflect the perceiv... more It has been suggested that a driver"s hand position on the steering wheel can reflect the perceived risk of the road context (Walton, D. & Thomas, J.A. (2005), Naturalistic observations of driver hand positions. Transportation Research Part F, 8, 229-238, Thomas, J.A. & Walton, D. (2007), Measuring perceived risk: self-reported and actual hand positions of SUV and car drivers. Transportation Research Part F, 10, 201-207). These original studies were based on field observations where only a part of the steering wheel could be viewed. In the present study hand positions were observed in a driving simulator during the performance of a demanding task; merging into motorway traffic. In the current study the whole steering wheel could be observed and hand positions were classified in three categories: high control, medium control, and low control. Differences in hand position between different traffic conditions were limited, and hand position did not correlate with self-reported risk or self-reported mental effort, but changes in hand positions do seem to coincide with changes in workload demand. It is therefore concluded that hand position can give some information about mental workload.