Federal Highway Administration State Planning and Research Funding
Illinois Department of Transportation
Federal Subaward from Univ of Illinois at Urbana-Champaign
About the research
The project evaluated two pre-manufactured pavement marking tapes (380AW and XRP-R) over three winter seasons at two different Illinois DOT locations (central and southern Illinois). The two products were installed on I-80 within a recessed groove in contrast to IL-3 where they were rolled in with the last pass of the asphalt finishing machine. Retroreflectivity was measured under three standard conditions including dry, wet-recovery, and continuously wetted. The 380AW tape measured 148 mcd under continuously wetted conditions after 3 winters on I-80 and overall measured significantly higher than the XRP-R tape under the two wet conditions (recovery and continuously wetted). The XRP-R tape performed well under dry conditions; however, wet-recovery retroreflectivity was below 100 mcd (after initial conditions) and continuously wetted retroreflectivity did not exceed 100 mcd. Short of a minimum retroreflectivity threshold for wet conditions, these findings will support IDOT decision making in terms of product selection where trying to enhance safety through providing higher levels of wet night visibility. The findings also highlight the potential negative impacts on performance when rolling these products in as opposed to placing them within a groove.