Reflective Airport Runway / Taxiway Glass Beads

• “Type III (1.9 Index of Refraction (IOR) airport beads had the best retro-reflectivity, initially and over time.” DOT/FAA/AR-02/128

Paint and Bead Durability Study by Holly Cyrus

• The retro-reflectivity data clearly show that the higher IOR (index of refraction, 1.9) Type III beads are far superior to Type I (IOR, 1.5) beads in initial and long-term retro-reflectivity. Thus, the Type III beads will be much more visible from farther distances…
A comparative Field Study of PermastripeTM Polymer Concrete and Waterborne Airfield Pavement Markings

by Kent Newman, PHD US Army Engineer Research and Development Center

• Using 1.9 index beads in place of 1.5 produces a more efficient retroreflective pavement marking system that is brighter and more visible at night (5).

TRB (Transportation Research Board) Paper 08-0775