One of the best methods for estimating blood alcohol content (BAC) in the driving population is through roadside breathtesting surveys that measure directly the BAC levels of drivers. However, there are barriers to conducting roadside breathtesting surveys in some states in the US. An alternative method for assessing BAC in the driving population may be to estimate BAC from self-reports of alcohol-involved driving collected via telephone surveys. This paper documents the results of estimating BAC in the driving population based on self-reported drinking, sex, and weight from a 1997 national telephone survey of US adult residents. These results are then discussed in light of findings from roadside surveys.