The RCD (Roller Compacted Dam-Concrete) method was developed in Japan for the rationalized construction of concrete gravity dams and has become one of the major dam execution methods in Japan. However, under the current social and economic conditions, it is now necessary to develop new technologies to achieve further rationalization, by shortening the work period, lowering the labor requirements, and achieving greater efficiency in order to cut costs. We are now continuously developing technologies to raise efficiency and speed than by the conventional RCD method. At the Kasegawa Dam (Kyushu Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism), parts of the dam body were constructed using our newly developed cruising RCD method, which achieves high-speed construction while maintaining a constant placement speed by placing the RCD concrete first and then the external concrete. At the Yunishi Dam (Kanto Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism), Continuous placement of concrete across the full surface of a lift was realized, speeding up the placement of lifts. The Japan Dam Engineering Center participated throughout the development and application of the cruising RCD method, and will use its knowledge to provide technological assistance for studies on efficient execution of concrete gravity dams in future. An outline of this technology is summarized in“ Engineering Manual for Cruising RCD Construction Method Technology” (published by the Japan Dam Engineering Center).