Verification of safety regulations to further reduce

In Japan, many locations (areas facing roads) do not attain environmental quality standard values (70dB or less for daytime, and 65dB or less for nighttime), mainly places located in major urban regions and along main roads. For this reason, it is concerned with ways to further reduce the noise generated by individual motor vehicles. From this aspect, first, noise rating scales for the amount of noise from individual vehicles, which can be evaluated not only physically (LAE and Lmax [dB]) but also psychologically (annoyance), were composed experimentally with the road vehicle noise simulator proposed in the previous papers [1][2]. Secondly, to attain the above standard values, the safety regulation values were verified in Nagano City. From the noise rating scales obtained, it can be found as follows: (a) In the case of steady running noise, “a little annoying ” corresponds to LAE=76dB (Lmax=74dB) and “annoying ” to 82dB (80dB). (b) In the case of accelerated running noise, “a little annoying” corresponds to 69dB (65dB) and “annoying ” to 78dB (74dB). Next, from the results (each LAeq, 10min is from 71.0dB to 74.4dB at a straight road, and 68.3dB to 71.7dB at a crossroads) measured at 7.5m from a microphone to a traffic line for 24 hours on weekdays, it can be predicted that, to attain the above standard values for all times and anywhere, it is necessary to regulate all of individual motor vehicles under Lmax=74dB. Consequently, it can be said that all safety standards should be implemented 74dB or less. 1