A previous study on the effective use of reflectorized materials on railway boxcars concluded that: (1) the larger the patches of reflectorized material used, the lower the level of illumination needed, and (2) larger concentrations of a given amount of reflectorized materials are more effective than smaller ones. This investigation was set up with the following hypothesis: for a given amount of reflectorized material an optimal utilization of this material must exist. Tests were conducted by giving each subject ten trials on each of four belts, all having the same amount of reflectorized material on the side of the cars. Forty subjects were used to determine the different types of belts reflectorized in different ways to represent miniature scale-size trains. Belt no. 1 seemed to be inferior, partly because the retinal image lag tends to produce the effect of a line which could not be distinguished as moving across a space within the critical angle of instant light falling on the side of a train. The differences between the other belts were not substantial narrowing down the problem to the possibilities of 1, 2 or 3 patches of reflectorization on the side of each car.
Abstract