01100690

Component

In an effort to obtain field luminance values provided by different sign sheeting materials, a set of white retroreflective traffic sign sheetings from various ASTM D4956 sheeting types and a newer microsprismatic full-cube sheeting were obtained, and white and green blank signs were constructed for each sheeting type. Blank white signs were positioned in typical right and left shoulder positions, and green signs were positioned in typical overhead mounted positions in the field. Field measurements of luminance were conducted from inside a 2006 model year Chevrolet Trailblazer sports utility vehicle at varying distances to the signs. In general, the microprismatic full-cube sheeting provided the highest luminances, whereas the beaded Type III sheeting provided the lowest luminances in all sign locations. Smaller samples cut out from the same rolls of sheeting as the signs were characterized in their retroreflective properties using a CCD-based retroreflectometer in the laboratory. These data matrices were then incorporated into a computer model known as the Tarvip model and scenarios were generated to simulate the field condition. In Tarvip, a median US headlamp beam pattern was used. Results show that field luminances were generally lower than the luminances suggested by TarVIP. However, in relative ranking of materials, the model findings notably agree with the field data. The agreement in relative ranking suggests that models such as TarVIP can be used reliably in determining relative performance of sheetings, but more headlamp data are needed to determine the variability in the distribution of actual field luminances.

01084478

08-0964

English

23p

2008

Transportation Research Board 87th Annual Meeting

DVD

Figures (4) ; Photos (2) ; References (32) ; Tables (3)

Headlamps; Highway safety; Luminance; Positioning; Sign sheeting; Simulation; Sport utility vehicles; Traffic control devices

Microprismatic retroreflective sheeting

Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors; Vehicles and Equipment; I72: Traffic and Transport Planning; I83: Accidents and the Human Factor

Transportation Research Board Annual Meeting 2008 Paper #08-0964

TRIS, TRB

Jan 29 2008 3:18PM