In its efforts to keep air pollution under control Rome's city authorities are cutting the number of private vehicles allowed on the roads mid-week. Admission to the area within the city's ring road (Gran Raccordo Anulare, or GRA) is alternated between cars with odd and even number plates every Wednesday afternoon between 15,00 and 19,00. On 18 February cars with odd-numbers are not allowed on the roads.

The ruling is estimated to have cut traffic by about 25 per cent on the days that it is in force but air pollution has remained close to danger levels. Cars and mopeds without catalytic converters are therefore banned from circulation within the GRA any day that the smog goes over the legal limits. In addition to this the city has emergency powers to decree a car-free Sunday whenever the levels of pollution go over the emergency levels for five consecutive days. This happened on the first Sunday in February and the city authorities are warning that it could happen again before the next official car-free Sunday on 21 March.

Meanwhile, traffic police are having a tough time enforcing the measures, and over 5,000 fines have been handed out since the schemes were introduced at the beginning of February.