Spillover research has shown that workday stress hampers commuting safety, while ego depletion research has demonstrated that prior self-regulation leads to performance decrements in subsequent tasks. This study sought to unite these two lines of research by proposing that ego depletion-induced alterations in attention and motivation are the mechanisms by which workday experiences spill over to the commute and impair driving safety. To examine the daily influences of these within-person processes on driving behavior in the post-work commute, this study adopted a daily survey design, wherein participants took an online survey immediately before and after each post-work commute across one work week. In these daily surveys, fifty-six participants (N = 56; n = 250 day-level observations) reported their workday self-regulatory demands; pre-commute levels of attention, motivation, and affective states; and driving behavior during the commute home. Using multilevel path analysis to isolate within-person effects, the current study found no evidence to suggest that workday self-regulatory demands lowered pre-commute attention and motivation, nor did it detect associations of attention and motivation with post-work aberrant driving. Results indicated that an ego depleted state might impair attention and motivation but not driving safety in the commute. Instead, the results pointed to the person-level factor of trait self-control as potentially having a greater impact on post-work aberrant driving than daily experiences. / M.S. / Research has shown that employees tend to drive more unsafely when commuting home after a stressful workday. However, most of this research has examined what about the person makes them drive more unsafely than someone else, but it is also important to understand what about the workday makes someone drive more unsafely one day than another day. I predicted that a workday containing more self-control demands would make an employee drive more unsafely when commuting home from work because facing more self-control demands would lower the employee’s attention and motivation for driving safely. To test this idea, I gave participants two online surveys per day for five consecutive days, Monday through Friday – one at the end of their workday (asking about their workday demands and current levels of attention and motivation), and one at the end of their commute home (asking about their driving behavior during that post-work commute). The data from my final sample of 56 participants (N = 56; n = 250 study days) showed no evidence to support my hypotheses: the amount of workday self-control demands was not found to associate with attention and motivation before driving home, and attention and motivation before driving home were not found to relate to driving safety during that commute home. On the other hand, I did find that a person’s general ability to maintain self-control was associated with their driving safety during the commute home (regardless of workday self-control demands). These results suggest that a person’s character might be more important in determining their day-to-day driving safety during the commute home than the self-control demands they face during the workday.