'Ghost kitchens' are taking over fast-food chains from Chick-fil-A to Wendy's

On Friday, Wendy's became the latest fast-food chain to mention delivery-centric locations without dining rooms or takeout, commonly called ghost kitchens or dark kitchens.

Abigail Pringle, Wendy's chief development officer, said during Wendy's annual investor day that dark kitchens would be a significant part of the chain's expansion strategy. Pringle said the chain planned to open two dark kitchens in the US by the end of the year, having already utilized the design internationally.