But a visit to TurnStyle last week left me almost convinced that Ms. Fine had achieved her stated goal — almost, because it will be impossible to judge fairly until it fills with as many as 90,000 pedestrians every weekday. (The passageway is outside the fare zone, so it costs nothing to enter.)

Image TurnStyle businesses will be required by their leases to remain open at least 12 hours a day, and are expected to serve up to 90,000 passengers on weekdays. Credit... Chang W. Lee/The New York Times

TurnStyle’s closest retail cousin is probably Grand Central Market. And that is more than a coincidence, since Ms. Fine was the director of real estate at the transit authority during the redevelopment of Grand Central Terminal.

What is appealing about TurnStyle is the density, variety and clarity of the space, designed by Thaddeus Briner and his colleagues at Architecture Outfit. The central public corridor is 27 feet wide, tight enough that a passer-by is conscious of storefronts on both sides. It is a small-scale evocation of a busy shopping street.

But not too busy. An enclosed conveyor belt has been constructed along one of the stairways to deliver goods and remove garbage without convoys of hand trucks.

Some dining spots will open fully to the passageway, with security gates that fold inconspicuously into side pockets. Tenants whose stores have solid glass facades cannot cover the windows with signs, or fill them with products that obscure views, according to the terms of the lease.

Spaces range from 219 square feet (Doughnuttery) to 780 square feet (the Gastronomie 491 market). Businesses are required by their leases to remain open at least 12 hours a day, Ms. Fine said. She said her goal was to keep TurnStyle open every day except Sunday.