A road information system provides the information required for safe management of roads, including road weather information, on road information boards etc. Since the installation of the first system in 1987, installations have increased yearly, and now systems for each main bureau and systems for offices of the Ministry of Land, Infrastructure and Transport in Tohoku, Kanto, Chubu, Kyushu and Okinawa have been installed. In the beginning, the systems were constructed with custom equipment developed by JRC, and performance and function of the systems have continually been improved over the years. We have been providing information not only to road managers but also to general road users through the internet, and setting up automated provision of information activated by guidance system. This report indicates the technology trends of the road information systems developed by JRC, and describes the future outlook for these systems.