In Japan, various entities have made efforts to realize manifold intelligent transportation systems (ITS) services using advanced technology and have developed the targeted Next-generation road system, ‘Smartway’. National Institute for Land and Infrastructure Management (NILIM) of the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) have placed the roadside equipment and prepared a new on-board unit to conduct on-road trials over the Metropolitan Expressways. The outcome of the series of tests has provided a valuable input to ’Smartway Demo 2007’, which gave a good opportunity to reveal our years-long research and development effort achievement in public. The paper reports the course of Smartway R&D the authors followed, what they have learned through the trial tests in serviceable road sections, and further reports the promotional and extensive effort to extend the service in the future.