2. Derivation of Leq(20 s) model based on the FHWA model
2.1. FHWA model
The FHWA model, which was proposed based on acoustic
theory and mathematical derivation, is a relatively complete highway
traffic noise prediction model. This model has been regarded
as the basic model for other highway traffic noise prediction
models [13–17]. The Leq(20 s) model can be derived based on the
FHWA model as follows.
The FHWA model is expressed as follows