Nihon Kotsu as the "Prince of Taxis." The company was founded as a sole proprietorship in 1928 and reorganized as a stock company in December 1945. It began as a limousine operator and expanded to taxi service in 1940. NK operates the most popular taxi hailing mobile application in Japan, Japan Taxi. Toyota invested 500 million yen in the app in 2017, followed by a second 7.5 billion investment in 2018. Tokyo Musen, a major rival of Nihon Kotsu in the Tokyo area, joined the app later that year in an effort to counterbalance foreign rivals such as Uber and Didi Chuxing.
Acoustic hailing device Acoustic hailing device An acoustic hailing device (AHD) is a specialized loudspeaker that emits high-power sound waves for communicating at a distance. AHDs vary in design, output, and usability. Acoustic hailing devices are acoustic devices capable of outputting highly intelligible sound at very high volumes. The distance at which acoustic hailing can be effective varies based on several factors including the sound level, directionality, and frequency of the acoustic source, the sensitivity and directionality of the receiver, and the transmission channel environment. The sound level diminishes or attenuates with distance. Consequently, as a general rule, higher source levels have greater