This study investigates the mechanical performance of various geosynthetic interlayer systems used in asphalt overlays to mitigate reflective cracking under monotonic loading conditions. Through a series of laboratory tests using a Crack Widening Device, the influence of reinforcement type (geotextile and geogrid) and placement depth (one-third, one-half, and two-thirds from the bottom of the specimen) was evaluated. Results demonstrate that reinforcement positioned closer to the crack initiation zone significantly enhances crack resistance, with the one-third placement yielding the highest fracture energy (GIC) and toughness improvement factor (TIF). Geotextile (Paving fabric-PF) reinforced specimens consistently outperformed both unreinforced controls and Carbophalt GB (glassgrid), particularly when embedded near the bottom. Conversely, reinforcements placed near the top surface showed diminished effectiveness due to delayed engagement with the fracture front. These findings underscore the importance of strategic interlayer positioning and material selection in extending pavement service life and optimizing overlay rehabilitation designs.