Steps to determining the LDN / CNEL sound level from Highway 101.
First, Caltrans Average Daily Traffic values are determined (Back AADT)
Settings for traffic count in acoustical simulation; 16,000 for northbound lane in this case.
U.P.R.R. train pass-by data is incorporated, plus the horn blowing at grade crossing.
At 22:22:15 hour, the peak value of sound was measured to be 94 dBA.
The LEQ for the hour between 22:00 and 23:00 is 72 dBA.
A penalty of 10 dB is assessed for sounds after 10 p.m.,
therefore the final sound level is 82 dBA for that hour.
(click to enlarge)
Traffic Modeling
