Cell Phones and Driving 1 Running head: CELL PHONES AND DRIVING Why Do Cell Phone Conversations Interfere With Driving?

While often being reminded to pay full attention to driving, people regularly engage in a wide variety of multi-tasking activities when they are behind the wheel. Indeed, as the average time spent commuting increases, there is a growing interest in trying to make the time spent on the roadway more productive. Unfortunately, due to the inherent limited capacity of human attention, engaging in these multi-tasking activities often comes at a cost of diverting attention away from the primary task of driving. There are a number of more traditional sources of driver distraction. These " old standards " include talking to passengers, eating, drinking, lighting a cigarette, applying make-up, or listening to the radio (Stutts et al., 2003). However, over the last 5-10 years many new electronic devices have been developed and are making their way into the vehicle. In most cases, these new technologies are engaging, interactive information delivery systems. For example, drivers can now surf the Internet, send and receive e-mail or fax, communicate via cellular device, and even watch television. There is good reason to believe that some of these new multi-tasking activities may be substantially more distracting than the old standards because they are more cognitively engaging and because they are performed over longer periods of time. This chapter focuses on how driving is impacted by cellular communication because this is one of the most prevalent exemplars of this new class of multi-tasking activity. Here we summarize research from our lab (e. Drews, & Crouch, in press), that addressed four interrelated questions related to cell phone use while driving. First, does cell phone use interferes with driving? There is ample anecdotal evidence suggesting that it does. However, multiple resource models of dual-task performance (e.g., Wickens, 1984; but see Wickens 1999) can be interpreted as suggesting that an Cell Phones and Driving 3 auditory/verbal/vocal cell phone conversation may be performed concurrently with little or no cost with a visual/spatial/manual driving task. Unfortunately, there is a paucity of empirical evidence to definitively answer the question. Second, if using a cell phone does interfere with driving, what are the bases of this interference? For example, how much of this interference can be attributed to manual manipulation of the phone (e.g., dialing, holding the phone) and how much can be attributed to the demands placed on attention by the cell phone conversation itself? This question is of practical importance; If the …