Road is a significant asset to any country, both in terms of physical investment, social integration, and economic benefits by linking agricultural areas to national or regional markets. The construction and maintenance of road infrastructure in Ethiopia is affected by several challenges like; scarcity of funds, poor performance, corruption, poor planning and project formulation, lack of coordination between stakeholders, poor project management system, and change orders. PPPs are the best option to overcome the above challenges, by capitalizing on the relational networks between governments and private investors. But the use of PPPs in the Ethiopian road sector has been limited. This study can investigate PPPs implementation challenges in Ethiopian road infrastructure project by the use of structured questionnaires and key informants' interviews. Through a comprehensive study of literature review, resulting in the identification and selection of 31 major challenges and 19 effective techniques of PPPs implementation and these variables were mapped in the mean score table. A questionnaire survey and key informants interview were carried out to identify the major challenges, effective techniques of PPPs implementation and to develop a PPPs implementation conceptual framework. The internal consistency was achieved using the SPSS relativity test; Cronbach's Alpha value is 0.922. A total of 96 questionnaires were distributed 72 were returned and 69 questionnaires were valid. The data generated were analysed using SPSS mean score descriptive statistics. A total of 13 key informants were interviewed. The study showed that the top five affecting factors are lack of effective institutional and regulatory framework, lack of PPP experience, improper feasibility studies and project analysis, improper value for money assessments, technical capacity gaps, lack of government support, and poor management. The results also showed that the top five effective implementation techniques are a favorable legal framework, the presence of a stable PPP policy, a stable political and social environment, a clear contractual arrangement, a strong private consortium, and provide an integrated solution. The attractive factors, major challenges faced by the implementation of PPP, and future effective PPP implementation techniques are mentioned by the key informants' interviews. The study also showed the PPP implementation conceptual framework in road infrastructure project. Keywords: Public-private partnership, Road, Infrastructure, Challenges