The aim is to improve air quality and reduce mobility problems, according to the City Council of Bilbao. The center of the city, delimited from the street Autonomy to the ria, has been declared a low emission zone. Polluting and highly polluting vehicles other than 0, ECO or C are prohibited. According to a Spanish decree, A-marked vehicles are "highly polluting" and B-marked vehicles are "polluting".
The measure therefore affects petrol cars registered before January 2006 and diesel cars registered before September 2015. According to the City Hall, half of the cars now circulating in the city are they, who will be exempt from the measure.
Regulations will only affect working days from 07:00 to 20:00 hours.