CHAPTER 1. INTRODUCTION
Advanced Traveler Information
Systems (ATIS) are intended to provide travelers with real-time information
on traffic and roadway conditions, vehicle navigation, roadway hazards, weather
conditions, and motorist services. In-Vehicle Signing Information Systems (ISIS)
and In-Vehicle Safety Advisory and Warning Systems (IVSAWS) are key components
of the broader ATIS program, and have the potential to provide drivers with
a wide variety of information via an in-vehicle display. ISIS is intended to
provide drivers with information that is currently depicted on external roadway
signs, such as non-commercial routing, warning, regulatory, and notification
information (McCallum, Lee, Sanquist, & Wheeler, 1995). IVSAWS is intended
to warn drivers of hazardous or unsafe conditions on the roadway ahead, including
accidents, construction zones, and the presence of emergency vehicles (Erlichman,
1992).
While the technical capability exists
to display ISIS and IVSAWS information in a variety of ways, little human factors
research exists to guide the selection of a preferred display design from among
the range of potential design alternatives. Key human factors considerations
associated with selecting ATIS display alternatives include the accessibility,
legibility, and understandability of ATIS information; the potential for ATIS
information to facilitate driver decision-making; and the potential for ATIS
information to distract the driver from the primary task of controlling the
vehicle. A wide range of display design parameters are relevant to these human
factors considerations. These design parameters must also be considered in the
context of characteristics of the driving population and the environment. Driver
characteristics include age and gender, and environmental characteristics include
the existing ATIS and road-sign infrastructure. Figure 1 shows how driver attitudes
and information-processing capabilities mediate the effect of ATIS design characteristics
on driving safety and warning compliance. This figure also shows the range of
variables selected for investigation. The general categories of ATIS design
and driving context include only a few of the many possible variables. ATIS
availability has been included as a design characteristic and as part of the
driving context. ATIS availability can depend on design decisions and it may
also depend on the roadway infrastructure.
In this study, we examine the effect of message style, the physical grouping or location of ATIS displays, the use of visual as opposed to auditory messages, the availability of the ISIS and IVSAWS information presented through an ATIS, and the availability of roadway information. This study will investigate how these factors affect driver compliance with warning messages, and whether particular ATIS message characteristics degrade driving safety.
ATIS and Roadway Information Availability
Objectives and Hypotheses of This Study
Trust in ATIS and Self-Confidence
Situational Awareness, Workload, and Information Assimilation