A new method of speed reduction in work zones is being investigated where an informational safety message is sent to drivers equipped with compatible receivers. The Safety Warning System, a currently available commercial technology, is being used as the test bed system. An experiment was set up within a work zone to detect the presence of vehicles equipped with radar detectors, stimulate them with police radar and a Safety Warning System message, and then observe their responses. Driver responses were measured by using specially modified radar guns, undetectable to vehicles with radar detectors. In this paper, the experimental design, data collection and data analysis methods are discussed along with some preliminary findings.