The Solo - Yogyakarta Highway section KM 9 – 15 is a national road to support the traffic of goods and services, but many passing freight vehicles are incompatible with the allowable loads that may damage the pavement. Therefore, the purpose of this research is to know the effect of overloading on age of plan and pavement thickness. This study used the method of binamarga 2005 to analyze the reduction in road of life span due to overloading load and binamarga method 2002 to analyze the effect of pavement thickness at the end of life span. Based on the analysis using the road of life span reduction formula with the value of Cummulative Equivalent Standard Axle (CESA) overloading load and standart load obtained the road of life span reduction numbers that occurred on Solo – Yogyakarta Highway section KM 9-15 is 8 years from the age of plan 20 years. Furthermore, the effect of overloading on pavement thickness at 20 years of age with standard loads indicates that it needs a pavement thickness for a surface is 24.5 cm (Laston), subbase is 11.5 cm (Sirtu Class A) and subgrade is 22 cm ( Sirtu Class B). Whereas the overloading load required pavement thickness for the surface is 27 cm (Laston), subbase is 27 cm (Sirtu Class A) and subgrade is 6.5 cm (Sirtu Class B). So it can be concluded that overloading leads to reduced road of life span and increases the need for pavement layer thickness. So that in terms of cost, the thickness of pavement layer due to the loading load is less efficient than due to the standard load.