Abstract
For effective noise abatement against road traffic noise, it is necessary to establish the precise calculation method of sound power level. This paper proposes a new method for calculating sound power level radiated from a single vehicle which starts from a special place, such as a signalized intersection and a toll-booth on a toll road. There are several reports which give sound power level radiated from a starting vehicle. Though the reports are useful, the factors influencing the sound power level have not been clarified yet. But using the calculation method proposed in this paper, one can consider how the factors, such as vehicle types, engine maximum power, load capacity, vehicle running weight, gradient of road, vehicle operation of a driver, and so on, influence the sound power level.
