Soon one in five Atlantans will be over 60.

To suit this age group, Atlanta needs to provide some basic necessities: transit, handy health care, a walkable neighborhood.

Planners are building just such a city, on two blocks of Auburn Avenue, a perfect community that will, alas, disappear after two days.

Demonstrating a philosophy they call “tactical urbanism,” the Atlanta Regional Commission and its partners in the Old Fourth Ward are, on Saturday and Sunday, creating a kind of paradise, with a farmer’s market, bike lanes, food trucks, lessons in planting an urban garden, an outdoor movie theater and musical performances.

For a while, Auburn Avenue will be a sweet place to live. And though the new additions will disappear with the weekend, they will show visitors and residents how one might create such an environment permanently, where Millennials and seniors can both enjoy a human-scale neighborhood.

“We don’t expect to change the world in two days,” said ARC spokesperson Cheryl Mayerik, “but it is a chance for folks throughout the region to come in and see what’s possible.”

For more information about the events on Auburn Avenue, go to on-myajc.com/1imGOJ3