The Japanese Road Traffic Law states that a vehicle horn should be used only in an emergency or in dangerous locations where a horn sign has been installed. However, drivers frequently use their vehicle horn as a signal when passing each other. Furthermore, pedestrians and cyclists are also honked at by drivers. There may be a negative effect of vehicle horn use on people outside the vehicle. Therefore, a questionnaire survey was carried out to ascertain the current circumstances of vehicle horn use. Respondents were asked about the latest or last-remembered instance of horn use in various situations, both when they were driving and when they were pedestrians. With regard to experiences of being honked at by another driver, the questionnaire included questions concerning place, traffic volume, the aim of horn use, the timing pattern of horn use, and the respondent's psychological reaction when honked at by another driver. It was found that drivers briefly honked their horn to express gratitude, or to gain another's attention, in various places. Long honks such as one long honk or two long honks mostly evoked negative psychological reactions in drivers, such as a feeling that the sound of the horn was startling, noisy, or irritating. Furthermore, pedestrians frequently had negative psychological reactions to horns used to gain their attention or to alert them to danger. More than 40% of nondrivers were displeased with the volume and sound quality of horns.
