of measurements of the maximum emission level of various single
vehicles at different speeds.
2.2. Relationship between Leq(20 s) and ðL0ÞEi based on the FHWA
model
As shown in Fig. 1, a receiving point (observer) was D0 metres
from the central line of the carriageway. If a single vehicle droved
from 10 s to 10 s, the 20 s continuous equivalent sound level of
the observer could be calculated by