<![CDATA[Determining an efficient and structurally reliable overlay thickness is essential for extending flexible pavement service life while minimizing construction cost. This study compares the overlay thickness design results of the AASHTO 1993 and MDPJ 2024 methods for the Tandun–Pasir Pangaraian road section, STA 20+400 to STA 22+400, Rokan Hulu, Riau, and evaluates the structural adequacy of both designs through mechanistic-empirical analysis. Falling Weight Deflectometer (FWD) data from the case study location were used as the primary input for the overlay thickness calculation in both design methods, providing a consistent basis for comparing their outputs against the existing pavement condition. The resulting overlay thickness was 7.5 cm using the MDPJ 2024 method, compared to 12.5 cm using the AASHTO 1993 method. Both design outputs were further analyzed structurally using the Pavement Past-Dean software to evaluate their capacity against fatigue cracking and permanent deformation (rutting) under repeated traffic loading. The mechanistic-empirical analysis showed that both overlay thicknesses satisfy the allowable strain criteria and are structurally safe against fatigue cracking and permanent deformation throughout the design period. However, the MDPJ 2024 method achieved this adequate performance with a considerably thinner overlay, indicating a more material-efficient design outcome than the AASHTO 1993 method. These findings support the adoption of MDPJ 2024, based on FWD-derived deflection data, as a more cost-effective overlay design approach for similar pavement rehabilitation projects in Indonesia. Keywords: Overlay, AASHTO 1993, MDPJ 2024, Falling Weight Deflectometer, Pavement-PastDean]]>
