Illustration depicting the relationship between wind direction and traffic noise distribution. Arrows indicate wind direction, with dotted lines showing the spread of traffic noise. Houses are illustrated with varied noise levels based on their position relative to the wind and the traffic source.

The illustration provides a visual representation of how wind direction affects the spread of traffic noise in a residential setting. A central road with vehicles is labeled as the ‘TRAFFIC ON ROAD', producing ‘TRAFFIC NOISE' which disperses in dotted lines. The wind direction is shown with arrows pointing from left to right. Two sets of houses are depicted on either side of the road. The houses situated downwind, to the left of the traffic source, are exposed to higher sound levels, while the houses upwind, to the right, experience reduced noise levels. The graphic underscores the importance of considering wind direction when assessing noise pollution in residential areas.