There are nearly 14,000 taxis in New York City, and sometimes that doesn’t seem like enough. But in a new study from MIT, researchers suggest that just 3,000 ride-sharing vehicles—be it a traditional taxi, an Uber/Lyft car, or a future autonomous robo-cab—could do the same job if each accepted up to four passengers. And if all passengers were willing to share their rides with nine other strangers in return for less traffic and lower cost, the city would need just 2,000 of such vehicles. [...]
MIT’s “secret sauce,” as lead researcher Daniela Rus puts it in the Proceedings of the National Academy of Sciences, is an algorithm her team developed to find the most efficient routes for carpooling vehicles to pick up and ferry multiple passengers to their destinations in a single trip. It first lays out all the requests and available vehicles on a map in real time. Then it analyzes all possible trip combinations to find the best one before assigning passengers each vehicle. If a new request appears during the initial trip, the system calculates whether a cab should pick up that new party. It will also send idling cars to places with high demand based on historical information. [...]
While the math might check out, David King, a urban planning professor at Arizona State University, is doubtful that the numbers would play out that dramatically in the real world—if they play out at all. For starters, the researchers assume that each taxi trip in that dataset carries one passenger (the data doesn’t specify this) when in reality, a lot of cabs are already shared by a party of multiple passengers. “Families get in them, or a couple is going out to dinner, so it’s not just a matter of once this vehicle picks up Person 1, it can then pick up Persons 2, 3, 4, and 5,” because the first party may have already filled up half of the seats, he says. His own research indicates that the average occupancy number is 1.6, which means the 430,000 trips made in one day during that week in 2013 could have carried as many as 688,000 passengers. (For her part, Rus says the parameters of the algorithm can be adjusted and would be tested over time to find that optimal solution.)
No comments:
Post a Comment