Updated, 8:18 a.m.

Good morning on this clammy Friday.

Picture Manhattan without a single car.

It is difficult to imagine, but that is exactly what the organizers of Car Free Day NYC want New Yorkers to consider today. On this Earth Day, the advocacy group is asking people to travel by subway, bus or bicycle, or to car pool, instead of driving.

The environmentally conscious idea caught on in Paris last year when officials there, just months before the city hosted an international summit that yielded a landmark climate accord, banned cars in part of the city and pedestrians flocked to the Champs-Élysées.

In New York City, several streets in Manhattan will be closed today: Broadway, between the Flatiron Building and Union Square; streets near Washington Square Park; and Wadsworth Avenue in Upper Manhattan, between 173rd and 177th Streets.

Dozens of local organizations are participating. Citi Bike is offering free rides to mark the occasion. Columbia University is providing free bus rides to campus.