It is a long slow ride to get to the top of a 1776 foot high tower, and construction workers do not get long lunches. So at the Freedom Tower in the World Trade Center they are hauling a Subway franchise up with them as they go.
A spokesperson for the Port Authority says in the Washington Times: "This amenity will save time by allowing construction workers to stay in the tower throughout their shift rather than having to go all the way up and down."
As the article noted later, it can take 45 minutes to get down from a tall tower, and construction workers only get a 30 minute lunch, so they rarely go down. Instead, most carry big plastic coolers with a full day's snacks, drinks and lunches. Being big guys who work at hard physical labour, they eat a lot; a five dollar foot long hero won't even get them started. So it is a nice amenity but it won't put mom and the plastic cooler out of business. It also is providing extraordinary publicity to Subway, who is risking absolutely nothing in exchange.
It appears that the idea came from the steel erector, DCM Erectors. The restaurant is part of a "hotel" of containers that include bathrooms, lockers and offices, pretty standard practice in the high rise business. They bid the project out to nine different companies, but Subway was the only one that didn't demand a guaranteed profit; according to Bill Grutta, the VP of operations for the erector:
"They came back with an offer to do this at cost, and if there's a loss, we'll subsidize it," Grutta said to the Associated Press, adding, "We're not looking to make money on the food, just to accommodate the ironworkers."
Smart guys, these Subway people, considering the publicity they got from it.