Answer
$ \approx 73 dB$
Work Step by Step
Given the decibel equation $B = 10 \log \frac{I}{I_{0}}$
with $I_{0} = 10^{-12} \frac{W}{m^2}$
Given the intensity of the sound of traffic at $I = 2.0 * 10^{-5} \frac{W}{m^2}$
Find the decibel level
$B = 10 \log \frac{2.0 * 10^{-5}}{10^{-12}}$
$B = 10 \log (2 * 10^7)$
$B \approx 73 dB$