A modelled estimate of environmental noise across the Lisbon
metropolitan area. These are not official measurements. Road, rail and
pedestrian-street sources come from OpenStreetMap; aircraft noise at
Humberto Delgado is built from real flight tracks (ADS-B history via
OpenSky), scaled to the official APA/ANA strategic map, plus a corridor
for the Cascais aerodrome; "people" noise is proxied by venue density
(bars, restaurants, terraces, miradouros). Rail noise reflects the real
train timetable and each line's service frequency (CP, Fertagus and
Metro GTFS); other sources use typical daily and weekly schedules.
Read the colours as a guide to how loud one street is against another.
They are not certified dB values.
