As from 1 January the Brussels city government is to introduce graduated traffic restrictions for days when pollution reaches alarm levels in the Belgian capital. When Alarm Level 1 is reached, a reduced speed limit will take effect in Brussels city centre and outskirts, while Alarm Level 2 will mean a reduction in traffic per se, using alternating odd/even number plates. Trucks weighing over 3.5 tonnes will be banned during rush hours and public transport will be free. Taxis and emergency services will not be affected by the new regulations.
Alarm Level 2 (over 100mg/m3 of airborne fine dust particles) has only been measured four times in the past ten years, the last time on 18-19 February 2008.