Although impaired driving is a widespread risk behavior among college students, there are limited tools for assessing its frequency and context to inform effective interventions. This study involved the development and evaluation of two innovative approaches for assessing impaired driving. The Impaired Driving Assessment (IDA), a modified Timeline Followback assessment, was compared to the Impaired Driving Electronic Assessment (IDEA), a web-based daily diary, among a sample of 15 college students over a 5-week period. We found high correlations between the IDA and the IDEA on all impaired driving outcome variables. IDEA respondents had high survey response rates but response rates were somewhat lower on weekends. Overall, this pilot study revealed that both the traditional and the electronic assessment approaches show promise for assessing impaired driving among college students, and additional research is needed to further explore their relative strengths and limitations.