Performance evaluation of pavement preservation using long-term pavement performance data

This paper investigated the effectiveness of pavement preservation on preventing different pavement distresses and identified the factors significantly affecting the effectiveness of preservation. Twenty-one specific sites with only one preservation treatment applied in the monitoring period were selected from the Specific Pavement Studies-3 (SPS-3) experiment of the Long Term Pavement Performance (LTPP) program. The SPS-3 focuses on the effect of four preservation treatments (thin overlay, chip seal, crack seal, and slurry seal) on pavement performance under five design factors (traffic, precipitation, temperature, existing pavement condition, and subgrade type). The pavement distresses considered in the analysis include fatigue cracking, longitudinal cracking, transverse cracking, and rutting. The effectiveness of pavement preservation was quantified using the distress ratio concept, which is associated with the areas under the distress curves after treatments and the distress curves with do-nothing. Statistical analysis results show that the effectiveness of preservation varies with the type of treatment and the target pavement distress. Among five design factors, precipitation shows the most noticeable influence on the effectiveness of preservation. The analysis results can aid highway agencies in selecting better preservation treatments based on local conditions.