Individual Selection of Driving Speeds: Analysis of a Stated Preference Survey

The diversity of drivers' speed selection in free-flow conditions has been assumed to originate from various human factors, mainly differences in driver characteristics and preferences. This study uses a stated-preference web-based survey with a sample of 290 participants to investigate the diversity of speed selection in relations to driver characteristics. The survey included newly developed scales of estimating driving risks and estimating personal difficulty of performing vehicle-related technical tasks. Also included were items on performing spatial tasks and drivers' own self-assessments. The analysis of the survey results revealed that newly developed latent driver characteristics, such as risk awareness and technical aversion, were found to strongly affect individual drivers' speed selection in a daily trip-daily speed selection. The perceived speed of the average driver, or average driver perception, also had a significant effect on drivers' own speed selection. In addition, some latent characteristics were found to have stronger effects in certain demographic groups. Implications for further speed-selection researches and road safety policies are discussed.