CHAPTER 1. INTRODUCTION
How reliable must traffic information
be for motorists to trust and accept such advice? People are slow to accept
and use new technology, even when the technology works reliably (Kantowitz,
Becker, & Barlow, 1993). Can an in-vehicle Advanced Traveler Information
System (ATIS) presenting real-time traffic information be commercially successful
when some of the information it presents is incorrect?
Noise is inherent in most large systems and highway networks often suffer perturbations. Congestion, delays, and accidents can sometimes make traffic information provided to motorists unreliable when it is received inside the vehicle. Drivers may therefore discount, or even ignore, such information, just as alarm signals can fail to produce behavior intended by the system designer (Sorkin, 1988). In some domains, a single bad experience is sufficient to prevent people from using a machine or service. For example, few people continue to feed coins into a defective vending machine or parking meter. Empirical data are badly needed to help the highway engineer select a level of system reliability and accuracy that will maintain the driver's acceptance and use of route guidance information. The goal of this research is to provide data to aid the ATIS designer in designating an appropriate level of system reliability that will be accepted by drivers and help to achieve the goals of Intelligent Transportation Systems (ITS), e.g., reducing traffic congestion (IVHS America, 1992).