Preventative maintenance treatments: Do they impact skid resistance on LTPP sections?

Conventional or routine pavement maintenance practices can be characterized as reactive in nature and not very cost effective. Preventative maintenance is an essential component of an effective pavement management framework or strategy. Dollars invested in implementing preventative maintenance strategies are significantly less than allowing a pavement structure to deteriorate until major pavement rehabilitation or reconstruction is required. Quantifying the effectiveness or performance of a Maintenance, Rehabilitation or Reconstruction (M, R, & R) activity is beneficial to an agency so they can determine what treatments or strategies offer the best "bang for the buck". Historically, pavement condition or performance is traditionally represented by its functional or structural performance. From a safety standpoint, the level of safety of a pavement has typically been measured as a function of its skid resistance. The Long Term Pavement Performance (LTPP) database can provide a reliable source of pavement data for assessing the performance of M, R, & R activities. The LTPP database has an extensive skid data set from sites located across Canada and the United States. As a part of this study, friction data from all SPS-5 sites in the LTPP experiment was used to examine skid resistance over time across various environment zones. The SPS-5 experiment examines the effects of various rehabilitation activities on flexible pavement sections. Another component of the study was to evaluate the performance of a number of commonly implemented preventative maintenance strategies. This paper presents a framework or methodology that can be used to evaluate the safety effectiveness of a pavement preservation strategy using LTPP data.