Think LA smog is bad? Air pollution got so nasty in Paris that authorities are cutting the city's traffic by half and reducing speed limits to roughly 12 miles per hour, Mashable reports. Starting tomorrow, personal vehicles with odd-number and even-number license plates will be banned on alternating days. (But electric and hybrid cars, taxis, and vehicles with over three people get a free pass.) Smog in the City of Light nearly obscured the Eiffel Tower this week, and air pollution topped European safety levels for the third straight day on Thursday, USA Today reports. Paris enacted similar emergency measures last year when pollution levels got high. "I am delighted" by the partial driving ban, "which I have been requesting for several days," tweeted Mayor Anne Hidalgo. (More Paris stories.)