Evaluation of an alternative traffic light change anticipation system.

A driving simulator was used to study the efficacy of an alternative signal phasing program. The new Traffic Light Change Anticipation System (TLCAS) utilizes a flashing amber in conjunction with a solid green indication to warn drivers of the impending onset of the solid amber indication. This new program was expected to provide drivers with additional information with which to make safe stopping or crossing decisions, and reduce behaviour associated with increased accident rates at signalized intersections. Additionally, a new measure of first response variability was introduced to evaluate the effect of the new program on driver behavior. The results indicated that the new system has the ability to reduce the number of red light violations. Of the 1148 target intersections, 43 violations were recorded for the regular program compared to 9 for the TLCAS program. The severity of decelerations was also impacted. The regular program displayed average maximum decelerations of 3.1 m/sec2 compared to 2.5 m/sec2 for the TLCAS program. However, the TLCAS program showed an increased variability in first response five times larger than the regular program. This finding, in conjunction with traditional measures, indicates that the new system performs comparably to an increased amber duration by increasing the potential for conflicting decisions between successive drivers approaching an intersection. Altogether, the results suggest that this alternative signal phasing program would not improve intersection safety. The findings also suggest that further study of the longitudinal behavior after the introduction of a TLCAS program may be warranted. Specifically, future studies should examine whether subjects engage in appropriate adaptive changes when confronted with a solid amber period warning after becoming familiar with the TLCAS.

Evolution, traits, and the stages of human courtship: qualifying the parental investment model.

Individual differences are explicitly connected to social interaction in Darwin's notion of sexual selection. Traits that increase the probability of successful reproduction will tend to increase in frequency. This process operates partly through differential choice, by one sex, of certain traits in the other. According to the parental investment model, females frequently have more stringent criteria for the traits they will accept in a mate because they have a relatively larger investment in each offspring. Because human mating arrangements often involve a substantial commitment of resources by the male, it is necessary to invoke a distinction between the selectivity involved during casual mating opportunities and the selectivity exercised when choosing a long-term partner. Ninety-three undergraduate men and women rated their minimum criteria on 24 partner characteristics at four levels of commitment. In line with an unqualified parental investment model, females were more selective overall, particularly on status-linked variables. In line with a qualified parental investment model, males' trait preferences depended upon the anticipated investment in the relationship. Males had lower requirements for a sexual partner than did females, but were nearly as selective as females when considering requirements for a long-term partner.

Reference points in spatial cognition.

The present research investigates the hypothesis that cognitive representations of large scale space contain elements that may be termed reference points, and that these points are used to define the position of adjacent places. The nature and function of reference points is explored in five experiments. Experiments 1 and 2 consist of tasks during which subjects judged the distance between known locations. The subjective distance between reference points and nonreference points was found to be asymmetrical, with the latter ordered in relation to the former. Experiments 3 and 4 employ reaction time tasks in which subjects attempted to verify the distance or direction from an anchor location to target locations. The data indicate that the relative referentiality of anchor and target locations influences verification time. The results of Experiments 1-4 suggest that reference points occur in spatial cognition and that these points provide an organizational structure that facilitates the location of adjacent points in space. Experiment 5 consists of a multiple regression analysis designed to clarify the semantic attributes of spatial reference points.