Summary: Impact of common distractions on driving behaviour and physiological parameters

Within this study, 66 experienced drivers (24 female, 42 male) took part in a field experiment on a closed track, thus investigating effects of different in-vehicle sources of distraction on driving performance.

The triggered distractive activities during the test drive were: grabbing an eyeglass case including taking out the glasses and placing them on the co-driver´s seat, opening and drinking from a water bottle, picking up and placing a dropped child´s toy, picking up a cell phone answering a call and lastly entering an address into a navigation system which was mounted to the windscreen.

Results show that all of the distractive activities had significant impacts on the driving and visual behaviour as well as on physiological parameters, valid for experienced drivers. Distractive effects could be isolated despite of sex, age or safety-relevant attitudes.

  • Conceiled Speedometer
Scope

The purpose of this study was to assess the impact of common distractive activities carried on driving. Driving behaviour was measured by means of objective driving data, physiological effects were collected via via mobile ECG and EEG. Questionnaire data was used to assess subjective distraction. The study consortium consisted of the Austrian Automobile, Motorcycle and Touring Club - ÖAMTC, the Austrian Institue of Technnology AIT, the Institute for Sleep - Wake - Research and Neurotraffic as scientific manager.

Method

Distractive activities carried out during driving can lead to significant driving errors or even crashes as required mental or physical resources are not allocated to the driving task. Within this study, 66 experienced drivers (24 female, 42 male) took part in a field experiment on a closed track, thus investigating effects of different in-vehicle sources of distraction on driving performance. The communicated task to study participants was to take part in a driving competition, where the aim was to drive several rounds on the closed track with a given speed range (30-50 km/h). To increase the task demand, the speedometer has been concealed. The actual purpose, the examination of distraction, was unknown to test subjects.

Driving performance was measured by means of speed choice, lateral and longitudinal acceleration behaviour (pdrive lite®) as well as gaze durations and time spent with both hands off the steering wheel. In order to assess individual cognitive work load and stress levels, physiological parameters derived from both EEG and ECG records have been collected during driving. Furthermore, questionnaires have been used before and after the test drives to collect individual driving habits and attitudes as well as subjective assessments regarding the experienced distractions during the test drive.

The triggered distractive activities during the test drive were: grabbing an eyeglass case including taking out the glasses and placing them on the co-driver´s seat, opening and drinking from a water bottle, picking up and placing a dropped child´s toy, picking up a cell phone answering a call and lastly entering an address into a navigation system which was mounted to the windscreen.

Results

Results show that all of the distractive activities had significant impacts on the driving and visual behaviour as well as on physiological parameters, valid for experienced drivers. Distractive effects could be isolated despite of sex, age or safety-relevant attitudes.

Furthermore results show that apparent distractive activities negatively influence solving the driving task, such as handling with a navigation system. However, more significant are the findings that distractions perceived less dangerous, such as manipulating with a drinking bottle or reaching for items, have considerably distractive impacts as well. Insofar the result seems of specific importance as the latter mentioned activities were mentioned to be carried out frequently during daily driving.

Implications

To put these findings into perspective, one has to take into account that the described effects were obtained in a relatively low speed range under optimal driving and environmental conditions (daylight, dry road, no traffic) on a closed track, and subjects were fully focused on solving the driving (competition) task.

In the light of traffic safety, the study clearly shows that distractive activities perceived less demanding nevertheless pose a considerable safety risk.