Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Arts and Sciences



First Advisor

Dr. Mark T. Fillmore


Alcohol intoxication represents one situation an individual might increase their amount of risk taking when driving. This dissertation is comprised of three studies that investigate the mechanisms by which alcohol increases driver risk-taking. Study 1 examined the effect of alcohol on driver risk-taking using a proxemics approach. The study also tested whether alcohol-induced increases in risky driving co-occurred with pronounced impairment in the driver’s skill. The study also examined whether the most disinhibited drivers were also the riskiest. Indeed, alcohol increased driver risk-taking and impaired driving skill. The study also revealed risky driving can be dissociable from impairing effects on driver skill and that poor inhibitory control is selectively related to elevated risky driving. Studies 2 and 3 built on this work by addressing whether the apparent dissociation between behavioral measures of driver risk and skill was mediated by perceptions the drivers held. While maintaining the distinction between driver risk and skill, Study 2 tested the relationship between drivers’ BAC estimations and their tendency to take risks on the roadway. Drivers who estimated their BAC to be lower were the riskiest drivers following both alcohol and placebo. Study 3 addressed whether risky driving could be increased by environmental factors that shape perceptions the driver holds. There is evidence post-licensure training programs might inadvertently generate overconfidence in drivers’ perceived ability to operate a motor vehicle and thus fail to perceive dangers normally associated with risky driving behavior. To test this hypothesis, twenty-four drivers received either advanced skill training or no training in a driving simulator. Drivers who received skill training showed increased risky driving under alcohol whereas those who received no training tended to decrease their risk taking. Trained drivers also self-reported more confidence in their driving ability. Taken together, these studies represent a large step towards the betterment of laboratory-based models of driving behavior. The work highlights the importance of distinguishing between driver risk-taking and driving skill. The studies also identified that drivers’ personal beliefs influence alcohol-induced risky driving; this suggests training programs focused on correcting drivers’ misconceptions might be most efficacious in reducing their risk taking on the roadway.

Digital Object Identifier (DOI)