The need for speed? The relationships between driver traits and speed choices during a naturalistic drive

Questionnaire based studies and those using driving simulators have provided convincing data that drivers prone to becoming angry drive faster. In contrast, anxious drivers tend to be more cautious in their driving style. Only a few studies have examined this in real traffic conditions, and these have often relied on an experimenter or instructor being present in the vehicle, which may confound the results. The aim of the current study was to examine the relationships between anxiety and anger traits, driver mood and speed and braking behavior while driving in real traffic conditions without an observer present in the vehicle. A total of 19 drivers (males = 12, mean age = 30.84, ± 7.88 years) holding a valid, full Victorian driver license, participated in the study. Drivers drove an instrumented vehicle along a predetermined 38 km route in the south-eastern suburbs of Melbourne. Mood (tension, sadness, anger, vigor, confusion and happiness) was measured before and after the drive and anger and anxiety propensities were also obtained. Drivers were also asked to think aloud during the drive, and verbal assessments of the driving situation were recorded. Overall, trait propensities for anger and anxiety were low, and this was evidenced by low levels of negative mood states both before and after the drive and no significant changes in these moods across the drive. However, despite the low propensities for anger and anxiety while driving, anger and anxiety shared relationships with speed and braking behaviors. Over the entire drive, drivers prone to anxiety tended to exhibit more braking behavior, but no differences in average or variation of speed emerged. In contrast, trait anger propensities were unrelated to driver behavior; however, drivers who had slower speeds throughout the drive tended to have increased anger at the end of the drive and also tended to discuss speed more as they got closer to the end of the drive.