Tarvip,a PC-Based Visibility Model for Normal and Ultra-Violet Activated Pavement Markings

Development of TarVIP 1.0, a computer model for predicting the detection distances of normal and UV activated pavement markings was recently completed at the Operator Performance Laboratory (OPL). Two Sherwin-Williams UV activated pavement marking samples, four UV headlamp units (Ultralux, Visteon, Cibio and Labino brands), and the UV filter covering the Labino UV headlamp unit were characterized in terms of their fluorescence coefficients, spectral emissions, and spectral transmissivity, respectively. The TarVIP model properly accounts for a complete three-dimensional representation of the roadway-headlamp-driver geometry. Veiling luminance due to fog is modeled using the Mie Scattering theory. The model consists of physical and human performance subsystems. Besides the aforementioned physical subsystem items, the human performance subsystem uses an extensive human visibility contrast threshold database to represent the human capabilities and limitations of pavement marking detection. The model was used to obtain the visibility distances under various levels of fog density, UV activated pavement marking and UV headlamp efficiencies. The resulting visibility distances show some potential benefits and some inadequacies of the UV headlamps and UV activated pavement markings.