Figure 5
NO 2 concentration according to the CET street classification. 1 = LOC – Streets only with local traffic, low traffic density. 2 = COL – Local and intermediate traffic, predominance of local traffic and median flow of vehicles. 3 = ART – Local and intermediate traffic, and median to high flow of vehicles. 4 = VTR – Avenues that collect all traffic and give access to different destinations and have high traffic density.