Abstract: While there are several different factors that contribute to traffic accidents, speeding certainly seems to be one of the more prominent ones. Previous studies have found a strong relationship between speeding and accident risk, with higher speed generally increasing accident propensity. However, there is still no consensus on the best way of measuring speeding behavior. Previous research has utilized various sources of speeding data, such as self-report measures and driving simulators, with each of these sources having their own limitations. In the present study, we explored the behavioral validity of three different assessment methods of speeding – 1) a direct self-report measure (self-reported speeding violations), 2) an indirect self-report measure (self-reported speeding norms), and 3) an objective measure (driving simulator). On a sample of 46 participants, we found that, regardless of the assessment method, traffic offenders exhibited somewhat higher levels of speeding than non-offenders. However, the difference was significant only in the case of the direct self-report measure. Hence, our results suggest that self-reported speeding violations show higher behavioral validity than the other two methods. In the discussion, we offer some ideas that could improve driving simulators and simulator-based studies and contribute to better behavioral validity of such data.