Previous studies have shown that male drivers drive faster than female drivers, but there is no agreement on whether impulsivity could induce this sex difference, nor is there a cross-sectional comparison of the effects of different road environments. The purpose of this study was to verify whether impulsivity and impulse control could explain the sex differences in driving speed. A driving simulator study (study 1, N=41) was performed to investigate whether there were sex differences in driving speeds in two road sections of different complexity, and a questionnaire survey (study 2, N=163) was conducted to investigate the relationship between sex, impulsivity, impulse control and driving behavior of the participants. The results showed that male drivers drove faster on simple roads, but this difference did not show on complex roads. There were no sex differences in impulsivity traits, but male participants had significant lower levels of impulse control. The results also reveal a partial mediating role of impulse control in the relationship between sex and driving speed. These results suggest that impulse control can predict dangerous driving behaviors and is an important factor in explaining sex differences in driving speed.