Private participation in infrastructure (PPI) toll road projects have been used with ever-increasing frequency and skill around the world, both in emerging markets and in OECD economies. Developed and developing countries throughout the world have accumulated a diverse base of experience with the building and operating of toll road systems. However, most PPI projects generally need huge initial investment, making continued private funding very difficult. One of the most important factors in PPI is how to mitigate efficiently the risks that may arise in the course of the road projects. From this perspective, the chapter analyses PPI cases in the relevant regions and suggests how to facilitate PPI in the toll road projects through investment risk mitigation measures by successful government policy. Taking into consideration the financial difficulties of these regions, PPI is an essential element in Eastern Europe and Asian countries' highway development based on the public/private partnership principal.