The difference between the prediction results obtained using
Eqs. (7) and (8) was approximately 3 dB(A). This result meant that
Eq. (8) may overestimate the traffic noise to approximately 3 dB(A)
in this case.
Another situation was traffic noise prediction for a road segment
which is shorter than the distance of a vehicle driving during
20 s. As shown in Fig. 3, the length of the road segment was
assumed as 166.5 m, which was a quarter of the road length
(666 m, the distance a vehicle is driving during 20 s in the example
mentioned above) in Fig. 4.When predicting the traffic noise of the
receiving point C in Fig. 3 using Eq. (7) under the same traffic
conditions mentioned above for the highway tunnel, the 1 h equivalent
continuous sound pressure level was