This decision, endorsed by the metropolitan council, means that vehicles with the yellow environmental badge, known as B-label, will not be able to circulate within the ZBE, which includes Barcelona and several surrounding municipalities. The measure is part of a broader strategy to reduce polluting emissions and promote more sustainable mobility by decreasing private vehicle use.

The ban aligns with a directive from the Generalitat de Catalunya requiring cities with over 50,000 inhabitants to limit the circulation of these vehicles by 2028, and by 2030 for heavy vehicles. Currently, B-label cars can circulate without restrictions in the ZBE under normal conditions, although they are already subject to temporary limitations during pollution episodes.

Barcelona's ZBE, operational since 2020, was a pioneer in Spain in restricting polluting vehicles. Initially, limitations applied to vehicles without an environmental label during working hours within an area of nearly 100 km². With the new plan, the AMB advances this regulation, responding to a demand present in various air quality plans to progressively withdraw B-label vehicles, still considered polluting.

This measure may generate debate, as B-label vehicles constitute a significant portion of the metropolitan vehicle fleet. Its final implementation will depend on municipal ordinance adaptations by local councils. However, the AMB considers the timeline "realistic" and believes the transition is facilitated by the decline in diesel vehicles and the increase in electrified ones. In addition to ZBE restrictions, the plan also includes expanding the AMBici public bicycle service and extending the cycling network to five municipalities in Vallès, the northern area of Baix Llobregat, and a part of Maresme.