With the increasing popularity of cellular phones and public concern about the safety of using phones while driving, there has been increased interest in tracking the incidence of driver cell phone use. This report presents the National Highway Traffic Safety Administration's (NHTSA) most recent results on this topic, which come from NHTSA's National Occupant Protection Use Survey (NOPUS). The survey estimated that during daylight hours, drivers of cars, trucks, vans, and sport utility vehicles used hand-held phones during 4% of their driving time in 2002, up from 3% in 2000. These results were obtained by observing actual traffic. In fact the NOPUS is currently the only source of probability-based observed national data on driver cell phone use.