Cellular telephone

Definition of Terms
In discussing the potential for cellular telephone use to adversely influence driving behavior and performance, the terms "cognitive," "cognitive capture" and "emotional content" are used. Within the context of this report, these terms describe the nature and degree of attention distributed between the tasks of driving and conversing on the phone. The task of conversing is seen as potentially having a major cognitive (thought) component where attention is focused on conversation rather than driving. The extent to which this occurs can significantly influence situational awareness (e.g., of the actions of other vehicles, the presence of a stop sign, etc.).
Cognitive capture refers to the situation where the driver may be totally "lost in thought," a condition which, in particular, could impair situational awareness. Where emotional content (i.e., personal involvement) in a conversation is high, such as arguing with someone over the phone, the likelihood of cognitive capture is increased. Those instances that require some level of cognitive involvement leading to a loss of situational awareness are viewed as increasing the risk of a crash.
Throughout this report, the phrase "cellular telephone" is used to designate the wireless communications hardware of interest. However, as pointed out earlier, a new, competing technology has emerged that also incorporates a similar architecture (i.e., handset) and hence similar concerns for safe use while driving. These Personal Communications Services (PCS) devices share many, if not all the display, control, implementation and user issues that have been associated with cellular telephone use in vehicles.
Since all of the research and data reviewed in this report has focused on "cellular telephones," this phraseology has been adopted throughout this report to simplify the presentation of materials. However, the discussion of issues and recommendations provided in this report apply to all wireless communications systems and associated hardware that might be used by drivers of vehicles.

Objective and Scope
Given the rising number of users of cellular telephones and the increasing number of services available through their use, it has been suggested that there may be a corresponding increase in cellular telephone related crashes. In addition, there have been a growing number of inquiries directed to NHTSA from the public, the media and members of Congress relating to the safety of using cellular telephones while driving. In response to this national level of concern, NHTSA initiated a program of research to develop a comprehensive body of knowledge on the subject. This report reflects one product of that research program.
The objective of this report is to assess the current state of knowledge regarding the impact of cellular telephone use on motor vehicle drivers while driving, and explore the broader safety issues associated with such use.
The primary scope of this report focuses on the potential impact of voice communications on driving. However, continuing development and availability of cellular technologies with integrated office functionality (e.g., network/Internet access, e-mail, paging, etc.) have also raised questions among some observers about the potential implications of such use on traffic safety. Thus, where relevant, consideration is also given to the possible impact of these technological developments.

Introduction
Cellular telephones were introduced to the American marketplace in 1983. The early models of these transportable communications devices included large battery packs and carrying cases, and cost thousands of dollars. Only a decade later, cellular telephones are even smaller than a package of cigarettes, and some models are capable of multitasking activities such as transmitting computer files, paging, maintaining continuous communications through e-mail and voice-mail connections, and even "surfing" the Internet.
The Cellular Telecommunications Industry Association (CTIA), the leading national organization which represents both wireless carriers and manufacturers, reports that there are currently over 50 million cellular customers in the United States, with an industry growth rate of about 40% per year. Although this rate is expected to decline in future years, it is estimated that there will be as many as 80 million users by the year 2000.
This rapid growth has brought with it a change in the demographics of cellular telephone users: from middle-aged businessmen to users encompassing all age groups, and social and economic classes, including those with less ability to task-share such as the elderly, and novice and occasional drivers. Facilitating the growth of the user base has been a reduction in the costs for cellular service, which has markedly declined, with an average monthly bill of only $51.00 for local subscribers, many of whom received their telephones for free. The cellular telephone industry is now worth an estimated $19 billion per year and growing. The number of "cell" sites (areas of service) across the nation is rapidly approaching 23,000. Given the moderate costs, availability of service areas, and ease of use, it is not surprising that cellular telephones are being rapidly adopted as fixtures in the American way of life.