All 13,000 taxis in New York City could be replaced by a fleet of 3,000 ride-sharing cars if used exclusively for carpooling, according to research published today by MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL). Instead of hailing taxis, passengers that use ride-sharing services for carpooling may lead to reduced traffic congestion, pollution, and fuel use. The CSAIL researchers used public data from NYC taxi rides published by the University of Illinois to develop the algorithm.