In this paper, the performance of geogrid and geotextile in asphalt overlay to delay the rate of reflective crack propagation has been studied based on the Response Surface Methodology (RSM). It was tried to investigate the effect of temperature, crack width, type of geosynthetics (polypropylene nonwoven and glass grid) and interactions between these parameters on the reflective crack propagation. In accordance with the obtained results of RSM, some equations were presented to predict with high accuracy the service life (N-f), vertical crack growth rate and initial strain using quadratic polynomial regression model. In addition, a new relationship between N-f and initial strain and temperature was assembled. Based on the obtained results it was identified that the glass grid has the best effect on improving the overlay performance. (C) 2015 Elsevier Ltd. All rights reserved.