“How are the people of the boroughs linked?” she said. “Well, the subway brings the people together of the five boroughs, and similarly the act of voting connects them as well.” (Quibblers may quibble that Staten Island’s rapid-transit line does not physically connect to the rest of the system, but an artist is allowed artistic license.)

The subway sticker beat out nine other finalists — five of which depicted the Statue of Liberty — in a voting process in which nearly 10,000 people took part. Anyone could submit designs for the contest, which was run by the city’s Campaign Finance Board.

The new sticker makes its debut on Primary Day, Sept. 12.

Ms. Dagata, 59, is not a professional artist; she runs a biotechnology company. But she paints as a hobby and was intrigued when the contest was announced in March.

Her design partner is a friend, Scott Heinz, who is a professional — he is an art director at the History Channel. He came up with the idea of having one colored “line” for each borough and whiting out the center of the O where the lines meet. “It’s about the simplicity of the subway map,” Mr. Heinz, 56, said.

Neither Ms. Dagata nor Mr. Heinz lives or votes in New York City. They are neighbors in Bronxville, in Westchester County, a couple of miles north of the city line. But they used to live in the city, and still work in it. And they have ridden the subway more times than they care to remember.