Conversing on cell phones while driving an automobile is a common practice. We examine the interference of the cognitive load of conversational dialog with driving tasks, with the goal of identifying better and worse times for conversations during driving. We present results from a controlled study involving 18 users using a driving simulator. The driving complexity and conversation type were manipulated in the study, and performance was measured for factors related to both the primary driving task and secondary conversation task. Results showed significant interactions between the primary and secondary tasks, where certain combinations of complexity and conversations were found especially detrimental to driving. We present the studies and analyses and relate the findings to prior work on multiple resource models of cognition. We discuss how the results can frame thinking about policies and technologies aimed at enhancing driving safety. Author Keywords
driving have become commonplace. The cognitive, visual, and physical demands of such tasks can compromise the primary task of driving. Users may often overestimate their ability to divide their attention with secondary tasks because of the sense that driving is near automatic in many situations and can thus be safely shared with other tasks. However, it may be difficult to switch full attention back to driving in a timely manner so as to observe and respond appropriately when driving challenges arise, and such attentional challenges can have costly consequences . The data linking the use of phones while driving to increases in accidents and fatalities has sparked legislation aimed at limiting cell phone usage during driving to handsfree configurations. However recent research has shown that using devices in a hands-free manner is no less harmful than the use of handheld devices . Thus, phone use would have to be stopped entirely to avoid the challenge they present to driving safety. Unfortunately, people are unlikely to give up phone interactions while driving, and complete bans of phone use in this setting are unlikely. Our goal is to better understand the interference between the cognition tapped for phone conversations and for driving. Insights about such potential interference would help to characterize better and worse times for phone conversations during driving, highlighting when drivers could more safely engage in phone conversations if absolutely needed. As a first step, we set out to understand how different types of cell phone conversations during varying levels of driving engagement affects driving performance and also the performance of the driver on the call itself. We sought to understand the findings in terms of interactions between cognitive resources used in driving and in handling common secondary tasks associated with phone conversations. We conducted a controlled study with 18 participants driving within an interactive driving simulator. The participants drove on routes composed of segments that posed different types of navigation challenges. While driving, the participants would occasionally have to respond to a cell phone call, pushing a button to initiate a hands-free interaction. The cell phone calls were one of three kinds of engagement: listen to news and facts (assimilate), answer questions (retrieve), and provide directions (generate). In addition, for each driving trial, we asked drivers to either focus mainly on their driving, on the conversation, or do their best to both drive and handle the phone-based tasks.
Driving, Attention, Dual task performance, Cell phones
ACM Classification Keywords
H5.m. Information interfaces and presentation (e.g., HCI): Miscellaneous. General Terms