Pavements deteriorate under traffic loads and climatic effects. Flexible pavements are formed by multiple layers. Each layer distributes and transfers the effecting loads to its subordinate. When road construction projects are prepared, the single axle load value is considered. Even though projects for State Highways in Turkey are prepared for 8.2 tons single axle load, the maximum axle load was initially increased to 10 tons and subsequently to 13 tons later on. Even though maximum value per single axel load was decreased to 11.5 tons in 1996, it is still over the initial project preparation value for the roads built before the adjustment. In addition, drivers load their vehicles above the allowed limits which results in faster deterioration of the pavement. Even if the pavement is not to be adversely affected by heavy traffic volume, it will still continue to deteriorate naturally due to climatic variables. In Turkey road condition assessments and traffic volume measurements are carried out by the General Directorate of Highways, which is also referred to as KGM. In Turkey, KGM is responsible for the condition evaluation, maintenance, rehabilitation and reconstruction of the road network totaling more than 64000 kilometers. This time consuming and expensive process is conducted by using expensive evaluation equipment known as road profilometre. However KGM only owns a few of these to make necessary measurements and evaluations on its road network. The deterioration measurements are calculated as "Ride Number" (RN) which varies from zero to five, with five representing the best condition of a pavement. KGM starts a rehabilitation process when the measured RN value for a road section drops below the critical limit of 2.5. Every vehicle type has a different effect on the road depending on its number of axles and its weight. Traffic volumes for all road sections in Turkey are measured for four different vehicle categories. These categories are car, bus, truck and trailers. To be able to evaluate the total effect, different vehicle categories on a road must be reduced into one. Each category's volume must be multiplied with its respective coefficient determined by the General Directorate of Highways. The resulting number is called "Equivalent Single Axle Load" (ESAL) value. In this study, a multiple regression model was introduced that can predict the RN value by using cumulative equivalent single axle load for the period of analysis and climate variables of the area where the pavement resides. Modeling is a process that requires extensive amount of data and complex calculations. This data evaluation process has the need for information technology support. In pavement engineering, the use of information technology has an immense power when data storage, process, and evaluation are concerned. The role of suitable, userfriendly software is essential for a fast, accurate, and applicable decision making process. Programming knowledge will not be sufficient by itself to develop such a useful software application. An effective result can be achieved by using the right hardware with an interface, programmed by an expert in the field of study. In this study a decision support system was used to process the high data volume. This decision support system has a large relational database management system (RDBMS), managed by MySQL. This database consists of traffic volume data for all State Highways along with climatic variables for each city in Turkey. This data was gathered by using the measurements conducted by KGM for the period beginning in 1993 through 2007 and detailed climatic data measured by Turkish State Meteorological Service. Forty road sections were determined for the multiple regression model to represent the State Highways. The dataset for these road sections includes cumulative traffic loads for the analysis period, and climatic data for the area upon which the road resides. Using SPSS statistical data analysis software, numerous combinations of multiple regression analysis were applied to different variations of the dataset. In addition, the stepwise method was also applied to determine the independent variables that predict the dependent variable RN with highest accuracy. The multiple regression analysis results indicate that cumulative ESAL, minimum temperature, solar exposure and precipitation levels were significant independent variables for predicting the dependent variable RN at a 95% confidence level. Detailed statistical test results verified the model validity, and revealed that the model was sufficient enough to predict the value RN. [ABSTRACT FROM AUTHOR]