As you might guess, the day was mostly meant to be educational. Mayor Anne Hidalgo has vowed to fight pollution in Paris, and to her that means reducing car use while increasing the number of bike and bus lanes. Theoretically, a "car-free" day raises awareness of alternative transportation methods and shows Parisians what life would be like with fewer cars on the streets.

Needless to say, pro-car lobby groups and avid motorists aren't fans of the idea. They already see Hidalgo as extreme, and believe the temporary car ban amounts to propaganda that makes cars look bad. However, they may be on the losing side of this battle even if Paris were to ditch no-car days. Both tech companies and automakers are anticipating a time when personal car ownership declines in favor of ridesharing, especially once self-driving cars hit the road in earnest. In that sense, Paris is just offering a peek at a future where you're unlikely to take the wheel unless it's absolutely necessary.