Strong yellow-green (SYG) is one of the unassigned colors listed in the FHWA’s Manual on Uniform Traffic Control Devices. Fluorescent SYG is promising because it appears to be more conspicuous in low-light conditions than conventional yellow signing materials. FHWA has conducted an extensive evaluation of SYG used for signs that warn drivers of nonmotorized hazards. North Carolina State University conducted one of the largest evaluations of SYG signs. The evaluation consisted of three parts: a traffic conflict study, a laboratory study, and a survey of pedestrians and drivers. The survey assessed driver perceptions of SYG warning signs at midblock pedestrian crossings. The researchers conducted the survey at four locations, which differed in pedestrian activities and saturation of pedestrian crossing signs. The study found that respondents thought that the SYG signs were more conspicuous, induced greater alertness in road users, and had a stronger association with caution. The respondents indicated that the aesthetic impact of the signs on the surroundings was no worse than that of standard yellow signs, and they generally recommended the use of SYG signs even when they were informed that the costs may be higher. The researchers also found that increases in travel frequency through the area in which the SYG signs were installed and increases in driving through that area in poor light conditions increased a respondent’s chances for noticing the SYG signs. Women and drivers between the ages of 36 and 45 generally gave SYG signs higher ratings than did other drivers. The results of this survey are described.
Crash Risk Prediction Modeling Based on the Traffic Conflict Technique and a Microscopic Simulation for Freeway Interchange Merging Areas
