Citation

Nixon W. Transp. Res. Circular 2008; (E-C126): 572-582.

Copyright

(Copyright © 2008, U.S. National Academy of Sciences Transportation Research Board)

DOI

unavailable

PMID

unavailable

Abstract

During the winter of 2005–2006 a new pavement overlay was tested for performance under winter conditions. The overlay uses an epoxy or polymer base, with a specially selected dolomitic limestone aggregate. The combination of the two creates a surface that is capable of retaining ice-control chemicals at the surface for much longer than regular pavements or overlays. The purpose of the testing during the 2005–2006 winter was to determine how well this new overlay (the SafeLane overlay system) performed and to measure the potential benefits of using such an overlay. In total, nine sites were considered in the performance tests, located in Texas, Wisconsin, Indiana, Ohio, Virginia, and New York. At one of these sites (the Wolf River Bridge in Crandon, Wisconsin) the overlay was installed during 2003. All the other sites were installed during 2005. Of the nine sites, seven were bridges, one was an exit ramp from a turnpike, and one was an on ramp to a bridge. Five of the bridges were on divided highways and only one carriageway of the bridge received the overlay, thus allowing a direct comparison with the control site on the other carriageway. The performance of the overlays was examined with three particular issues in mind. First, did the overlay create any problems when liquid chemicals were applied? Second, did the overlay delay the adhering of snow and ice during winter storms, and if so, was this delay achieved with more, the same, or less chemicals than the control section of the highway? And third, did the overlay provide any measurable improvement in safety for the traveling public? This paper will present the detailed results of the performance testing. In summary, there were no problems experienced with application of liquids to the overlay, the overlays consistently stayed free of snow and ice longer than comparable control sections, and could be kept clear with fewer chemicals than control sections, and finally significant safety benefits (in the form of reduced numbers of crashes) were observed for the overlays. Additional performance testing of the overlay system is planned for the 2006–2007 winter, with many additional sites being included in this second phase of testing.