Italian police have handed out 162 fines in less than three hours to people ignoring a driving ban in Milan.
The temporary ban started at 10:00 local time (09:00 GMT) and will last until the early evening in an attempt to curb the city's smog problem.
But within just two and a half hours, police were handing out fines of 164 euros (£137) to those flouting the ban.
Milan was named Europe's most polluted city in 2008 and smog remains a recurring problem.
By 12:30 local time on Sunday, there had been 621 checks on people not adhering to the "Sunday walk" day, local media reported.
The ban does not apply to electric vehicles or the disabled. Some streets have remained open, in particular to allow access to AC Milan's San Siro Stadium.
It is not the first time cars have been banned from within city limits and it has not proved popular with everyone. Regional counsellor for the environment Raffaele Cattaneo called it "demagogy with a green sauce".
Last month, several Italian cities, including Rome as well as Milan, temporarily banned diesel vehicles after pollution levels soared.
Vehicle emissions are the most common source of microparticles hazardous to health, known as PM10s and PM 2.5s.