Attacker/defender models have primarily assumed that each decisionmaker optimizes the cost of the damage inflicted and its economic repercussions from their own perspective. Two streams of recent research have sought to extend such models. One stream suggests that it is more realistic to consider attackers with multiple objectives, but this research has not included the adaption of the terrorist with multiple objectives to defender actions. The other stream builds off experimental studies that show that decisionmakers deviate from optimal rational behavior. In this article, we extend attacker/defender models to incorporate multiple objectives that a terrorist might consider in planning an attack. This includes the tradeoffs that a terrorist might consider and their adaption to defender actions. However, we must also consider experimental evidence of deviations from the rationality assumed in the commonly used expected utility model in determining such adaption. Thus, we model the attacker's behavior using multiattribute prospect theory to account for the attacker's multiple objectives and deviations from rationality. We evaluate our approach by considering an attacker with multiple objectives who wishes to smuggle radioactive material into the United States and a defender who has the option to implement a screening process to hinder the attacker. We discuss the problems with implementing such an approach, but argue that research in this area must continue to avoid misrepresenting terrorist behavior in determining optimal defensive actions.

Walking is a mode of travel used by billions of people daily. Facilities that promote walking such as crosswalks often involve sharing space with conflicting vehicular traffic. These areas are not immune to receiving pedestrians that either do not obey or do not understand today’s pedestrian signals, which are used to communicate periods of safe crossing. Therefore, improving comprehension would subsequently improve safety and crash rates. The Traditional Pedestrian Signal in the United States displays an illuminated man and a hand to indicate a cautionary-crossing period, a transition period, and a crossing-prohibited period. This signal type was evaluated and compared to a relatively new Experimental Pedestrian Signal. The Experimental Pedestrian Signal presented in this paper utilized the figure of a walking man changing only by the colors green, yellow, and red. Both signals were analyzed to identify the phases that best communicated the intended action. Video files depicting a Traditional and Experimental Signal were administered with a questionnaire to test the comprehension of rural and suburban participants. The results indicated that the Experimental Pedestrian Signal was not better understood than the current Traditional Signal, although a vast majority of participants preferred the Experimental Signal. The lowest comprehension occurred during the transition phase for both pedestrian signal types. The results also suggest that the interpretation of the yellow color varies by location and may invoke mixed responses if incorporated in pedestrian signals. A more appropriate solution may be to combine both symbolic and color cues into future pedestrian signals.

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