This report describes the results of an experiment that examines the effect of Advanced Traveler Information Systems (ATIS) devices. Specifically, it examines how In-Vehicle Safety Advisory and Warning Systems (IVSAWS) and In-Vehicle Signing and Information Systems (ISIS) characteristics affect driver compliance with warning messages and driving safety. These characteristics include display modality, message style, and display location. A general issue facing ATIS designers is the concern that ATIS warning messages may go unheeded by drivers. Therefore, a critical element of ATIS design concerns is making information easily accessible and compelling so drivers comply with the warnings. The results show converging evidence that ATIS warnings can generate greater compliance compared to road signs. Another general issue that faces ATIS designers is the potential for ATIS devices to undermine driving safety. The results of this experiment show that ATIS devices can undermine driving safety by fostering an overreliance on ATIS information. The results also show how particular ATIS design characteristics can minimize the overreliance and its negative effects on driving safety.