The main goal of this mapping study was to find out how much the traffic lights affect the city’s pollution and therefore the way to do this was to measure the Co2 emissions of cars on traffic lights. The mapping process was divided in three phases that resulted in a final Co2 emission map [based on diagramms and numbers]. It’s a mapping technique that can be applied throughout not even Barcelona but throughout all cities. It’s obvious that the cars emit much more while idling at a traffic light , so in such locations the map is full of “bubbles”. Yet, wherever the circulation is controlled basically with traffic signs the pollution is remarkably less. More detail appears on the A1 presentation