For example, in San Francisco, Lyft's carpooling service makes up 50% of rides.

Professor Daniela Rus of MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) researched actual taxi data and determined 3,000 ride-sharing cars could replace every cab in New York City.

Let's turn our attention to the actual report: carpooling apps could reduce traffic 75%. 

Led by Professor Daniela Rus of MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL), researchers developed an algorithm that found that 3,000 four-passenger cars could serve 98 percent of taxi demand in New York City, with an average wait-time of only 2.7 minutes.

The team also found that 95 percent of demand would be covered by just 2,000 ten-person vehicles, compared to the nearly 14,000 taxis that currently operate in New York City.