Driver inattention is a major contributor to highway crashes. The National Highway Traffic Safety Administration estimates that at least 25% of police-reported crashes involve some form of driver inattention. Driver distraction is one form of inattention and is a factor in over half of these crashes. Distraction occurs when a driver "is delayed in the recognition of information needed to safely accomplish the driving task because some event, activity, object, or person within or outside the vehicle compels or induces the driver's shifting attention away from the driving task." The presence of a triggering event distinguishes a distracted driver from one who is simply inattentive or "lost in thought." The AAA Foundation for Traffic Safety awarded a contract to the University of North Carolina Highway Safety Research left to conduct research on the role of driver distraction in traffic crashes. The goal of the project is to identify the major sources of distraction to drivers and the relative importance of the distractions as potential causes of crashes. This report presents the results of Phase I of the project. Included is a descriptive analysis of five years of the NASS Crashworthiness Data System (CDS) data, along with an analysis of narratives for two years for both CDS and North Carolina data. The descriptive analyses and the narrative analysis were done to provide input for developing a more comprehensive taxonomy of driver distractions; the taxonomy will guide future field data collection efforts.