Thin lift surface may not be the best option if rutting exceeds which value?

• A. 0.25 inches
• B. 0.75 inches
• C. 0.5 inches
• D. 1.0 inch

Answer: (C)

Rutting depth shows how much the pavement has permanently deformed under loads. A thin lift mainly cures surface roughness and seals the top layer, but it adds only limited structural support. When rutting is about a half inch or more, a thin overlay can’t adequately address the underlying deformation and may leave a rough, unstable surface that continues to rut and reflect distress. In that situation, a thicker overlay, milling to remove the rut, or a full-depth repair is a better choice to restore both ride quality and load-carrying capacity. If rutting is less than half an inch, a thin lift can be appropriate to restore surface smoothness and seal the pavement.