Ichiro Kageyama, Yukiyo Kuriyagawa, Tetsunori Haraguchi, Tetsuya Kaneko, Minoru Nishio and Atsushi Watanabe. Study on Road Friction Database for Traffic Safety: Construction of a Road Friction-Measuring Device. Inventions2022,https://doi.org/10.3390/inventions7040090. 2022. 7(4). 90. 90-90