The degree of price variations referring to each specific type of construction shall be measured by rnspecific price indices, in order to achieve more accurate results. In Ethiopian Road Authority, Price rnIndex is commonly used for price adjustment administration in the escalation of road construction rncosts. This study aims to improve price adjustment administration in federal road projects. The rnobjectives of the study report in this thesis are assessing current price indices determination practice rnwhen original source cease to publish indices, assessing reliable sources to minimize ceasing of rnpublishing indices and developing guideline for price adjustment administration system when rnsupplier cease to exist and replaced by new source. This research covered, the studies on improving rnprice adjustment administration in federal road projects. Moreover, price adjustment administration rnwhen suppliers cease to published price indices were analyzed by trend, T-tests and regression rnanalysis techniques, to obtain models to predict the future values of the new sources of indices, rnwhich was a way enabling the prediction of the future indices of a price adjustment in federal road rnprojects. Using a detailed literature review, a quantitative data collection approach, data was rncollected from Ethiopian Road Authority payment certificates, to see the trend of price adjustments rnof key construction cost inputs (cement, bitumen, fuel and steel), National Bank of Ethiopiaâ€™s rnwebsite (currency exchange ETB to USD) and different local and international road construction rnmaterial suppliersâ€™ websites. In this thesis, some descriptive statistical methods have been used for rnthe analysis of Three DB case study projects that are completed under RSDP IV. The projects are rnChole magna, Dire Dawa- Dewelle and Pawi-Junction. The result is analysed using trend, T-test and rnregression analysis methods. The analysis resulted that, NOC should be used as a new source for rnChole magna and Dire Dawa-Dewelle projects. Producer Price Index (PPI); Petroleum from Bureau rnof Labour Statistics (BLS) U.S should be used for Pawi Junction-Fendkia-Ayma project. Finally, rnbased on the analysis of the results, this research developed guideline to enable professionals to rndetermine the new source of index using a common guideline and help to create common rnunderstanding