More Americans will stream into subway trains and buses when vacationing in U.S. cities this summer, according to an American Public Transportation Association survey released Friday.

Some 28 percent of public-transit users said they will be more likely to use buses and trains while visiting a city this year than last year, according to the survey of 33,000 adults, with saving money the primary reason.

This summer, many city tourists will be saying 'no cab fare, no rental car, no problem,' William W. Millar, the president of the APTA, told a press release.

Some 62 percent of the people surveyed said saving money was their chief concern, while 61 percent said public transit would save them the worry of finding a parking space.

Thirty-nine percent said they would chose public transit because it is better for the environment.

Transit use will be highest in New York City, with 48 percent of travelers visiting the city opting to use buses and trains. Tourist transit use will also be high in Washington, Boston and San Francisco, according to the survey.

While most tourists are choosing public transit to keep green in their wallet, transit offers environmental benefits as well, said APTA's Millar.

According to the APTA, using public transit produces 95 percent less carbon monoxide, and 50 percent less carbon dioxide and nitrogen oxide per passenger than using a car.

Carbon dioxide and nitrogen oxide are greenhouse gases that scientists say contribute to global warming.