Recent improvements in manufacturing processes have allowed the development of a fluorescent, microprismatic sign material with a unique strong yellow-green color. Although this color is listed in the Manual on Uniform Traffic Control Devices, it is currently unassigned. Pedestrian accidents continue to be a major safety problem in the United States, and the Federal Highway Administration has requested research on the application of fluorescent strong yellow-green warning signs for pedestrian, bicycle, and school crossing applications. The research effort sought to evaluate the effectiveness of fluorescent strong yellow-green pedestrian warning signs in improving safety at midblock pedestrian crossing areas, using sound experimental methodology and encompassing multiple users and varied crossing conditions in several North Carolina cities. An experimental plan with a single treatment was used (replacement of existing signs with fluorescent strong yellow-green) and followed a model of before and after with a comparison site. The measures of effectiveness used were vehicle-pedestrian conflicts and motorist slowing and stopping. Results indicate that the fluorescent strong yellow-green treatment produced only marginal improvements in perceived safety at the crossing sites. Although the occurrence of motorists slowing and stopping increased significantly at three of the seven test sites, the proportion of vehicle pedestrian conflicts did not change significantly. Based on the results it is recommended that FHWA tentatively designate fluorescent strong yellow-green for nonmotorized applications until such time that long-term accident-based and cost-effectiveness research is available to justify permanent designation or alternative uses.