Reliability of variable message signs information: A field experiment study in Chongqing

A variable message sign (VMS), which is a key component of intelligent transportation systems, has been frequently used in the management of urban roads and motorways to provide drivers with real-time traffic condition information about a road section or area. Nevertheless, there is a lack of unified regulations for VMS design, which makes it difficult to accurately determine the understandability and legibility of VMS information. In practice, inappropriate designs of VMSs are common, such as overload of VMS information and excessive number of phases, particularly on the urban roads of China. Building on our earlier findings obtained by surveys, in this study, field tests were conducted to assess the reliability of VMS information in terms of the visual perception characteristics of drivers. For a full visual perception, the information displayed on a VMS must be reliable, i.e., it should be easy for drivers to detect, obtain, and understand the messages they require. Two basic theories—information theory and visual perception theory—were introduced to build a quantification model of VMS information, select evaluation indices, and design the experimental process. A total of 24 drivers participated in the field experiments and questionnaires. Five indices—information obtainment rate, periodic validity, driver subjective scoring and the corresponding UI (represents information intelligibility), and CE (represents information legibility)—were analyzed to evaluate their relationships to VMS information reliability. The results confirmed that the amount of information, and the scrolling period considering redundant distance, significantly affect the reliability of VMSs information. For static VMSs, the information obtainment rate and the subjective scoring decrease with increasing amount of information. The recollection accuracy of the drivers significantly declines when the amount of information shown increases to 90 bits, corresponding to an information obtainment rate of less than 0.8 and UI equal to 0. For dynamic VMSs, the information reliability deteriorates as the scrolling period shortens and the number of phases increases. Unreasonable reliability is found when the periodic validity is less than 0.9, i.e., the actual scrolling period is more than 10% less than the calculated one, corresponding to CE equal to 0. The reliability of information was evaluated by combining the subjective scoring of the drivers and a data-based statistical analysis and considering driving safety. Accordingly, it was recommended that 90 bit is the maximum amount of information to be shown on a VMS and that the preferred scrolling period of each phase of a dynamic VMS is 5 s. The results of this study support the objective of providing reliable information to drivers by addressing the problems related to the amount of information and presentation time for VMSs. These findings provide a basis for determining the thresholds for VMS information to promote practical and user-friendly designs of VMSs on urban roads.     

Examining generalization of motorist yielding at an adjacent crosswalk with variations of the gateway sign configuration

The gateway sign configuration has been effective at increasing motorist yielding and reducing speeds at crosswalks. A gateway configuration uses in-street signs at a crosswalk on each edge of the roadway and on each lane line. Although this intervention is effective at increasing motorist yielding at uncontrolled crosswalks, the limits of the intervention have yet to be tested. The present study examined if 1) the effects of the gateway intervention on one crosswalk would generalize to an untreated adjacent crosswalk, and 2) if the effects of an offset configuration of signs which partially treated each crosswalk could maximize the effects of that generalization. Experiment 1 showed that less yielding occurred at the untreated crosswalk than at the treated crosswalk, though yielding was higher than baseline. In Experiment 2, results showed that an offset gateway configuration could produce comparable levels of yielding at both crosswalks.     

The Influence of Self-Esteem on Cognitive Responses to Machine-Like versus Human-Like Computer Feedback

Abstract

Business school students (N = 49) who were preclassified as being either high or low in self-esteem (Texas Social Behavior Inventory) interacted with a computer that delivered either human-like, neutral, or machine-like feedback. In line with a compensatory, self-enhancement perspective (Baumeister, 1982), this experiment found that persons high in self-esteem generated more negative cognitive responses and made fewer errors when faced with human-like rather than machinelike feedback from a computer. Overall, however, persons low in self-esteem did not perform more poorly than did persons high in self-esteem.     

Signs in their times: introducing a review symposium on Robert Yelle's Semiotics of Religion

This essay introduces a review symposium on Robert Yelle's Semiotics of Religion: Signs of the Sacred in History (2013). It first reviews the book's argument, then offers a selective review of the six contributions to the symposium, along with aspects of Yelle's responses to these.     

Medical semiotics in the 18th century: A theory of practice?

Medical semiotics in the 18th century was more than a premodern form of diagnosis. Its structure allowed for the combination of empirically proven rules of instruction with the theoretical knowledge of the new sciences, employing the relation between the sign and the signified.     

NATURALISTIC METHODOLOGY IN AN EMERGING SCIENTIFIC PSYCHOLOGY: LOTZE AND FECHNER IN THE BALANCE

The development of a methodologically naturalistic approach to physiological and experimental psychology in the nineteenth century was not primarily driven by a naturalistic agenda. The work of R. Hermann Lotze and G. T. Fechner help to illustrate this claim. I examine a selected set of central commitments in each thinkers philosophical outlook, particularly regarding the human soul and the nature of God, that departed strongly from a reductionist materialism. Yet, each contributed significantly to the formation of experimental and physiological psychology. Their work was influenced substantively by their respective philosophical commitments. Nevertheless, the evaluation of the merits of their specific proposals, Fechner's psychophysics and Lotze's local sign hypothesis respectively, did not depend upon sharing their metaphysical views regarding the human soul or the nature of God. A moderate, but significant, distinction between the contexts of discovery and of justification aids in understanding this balancing act.     

Effects of route guidance variable message signs (VMS) on driver behaviour

Effects of route guidance Variable Message Signs (VMS) on speed and route choice were investigated in a field study on two sites on motorways. Two VMS were used in the study, which displayed information about a closed road section downstream on the motorways and recommendations for alternative routes. Route choice, speed and braking behaviour were compared between vehicles approaching the VMS while they displayed messages and while they were left blank without message. There was high compliance with the messages on the VMS. About every fifth vehicle changed route choice according to the recommendation, and almost none drove as far as the closed road section. Speed measurements of 3342 vehicles showed large speed reductions, and video observations showed that large proportions of vehicles braked while approaching the VMS. The speed reductions and braking manoeuvres can partly be attributed to attention overload or distraction due to the information on the VMS. However, a proportion of the speed reductions was due to chain reactions where one vehicle braked and forced the following vehicles to brake or change lanes in order to avoid collisions. Safety problems may result directly from distraction, or indirectly from the reactions of the drivers to the distraction.     

A PROMPT PLUS DELAYED CONTINGENCY PROCEDURE FOR REDUCING BATHROOM GRAFFITI

This study assessed the effectiveness of posting signs for reducing graffiti in three men's restrooms on a college campus using a multiple baseline across settings design. During baseline, graffiti increased almost daily in each of the three settings. Immediately following the intervention, no marks were made on any of the three walls. Results were maintained at 3-month follow-up. A possible explanation for the results is that the signs specified an altruistic contingency.     

Communicating safety with drivers via dynamic message signs

In recent years numerous transportation agencies have begun displaying creative safety messages like “get your head out of your apps” on dynamic message signs (DMS). DMS have been used traditionally to provide real-time information about travel times, weather conditions, construction, and incidents. Applying emotional and consequential concepts from protection motivation theory, which has a track record of leading to behavioral changes from public awareness campaigns, this study evaluates how the use of safety messages on DMS impacts driver perceptions. We find that emotions, but not consequences, impact self-reported driving behavior. Further, while drivers reported negative emotions would change their driving habits, positive messages were recalled far more often. Cell phone related messages were recalled most frequently despite being rarely displayed along roadways in Michigan where the study is conducted. Thus, the results support the use of positively themed messages with consequences that drivers perceive as realistic.