Subjective evaluation of retroreflective conspicuity markings : marking systems to aid in increasing visibility of coal hoppers at passive railroad grade crossing

This project had two primary objectives. The first objective was to design and administer a single questionnaire as part of a modified Delphi technique to obtain expert evaluations of eleven experimental retroreflective railroad car conspicuity marking systems. The second objective was to use the collected data and apply three different statistical techniques to evaluate what the expert respondents "perceive" to be the most effective marking system to increase the visibility of coal hoppers. The application of retroreflective markings to railcars is a novel idea, based on research that has shown retroreflective markings applied to large trucks improve conspicuity. Results from the study found that there was a definite consensus on which markings were the most and least effective passive retroreflective hopper car markings to be used as a warning device. The results of this study have reduced the number of marking designs to be laboratory tested. The most effective hopper car marking was #8 followed by #3, and #6 respectively. Each of the three were yellow markings on a black coal hopper. The least effective marking was #11 followed by #7. The #11 was the standard non-retroreflective marking. The results seem to indicate that yellow markings are preferred on black coal hoppers.