It's theoretically possibly to remove three-quarters of the taxis from New York's streets, drastically reducing congestion, according to a new study — as long you're happy to share a ride.
Researchers at MIT found that using ride-sharing services like Uber's UberPool, cities can cut down on the number of vehicles on the roads, reducing traffic and pollution and improving efficiency.
The researchers developed an algorithm that in their model was able to serve 98% of New York City's taxi demand with just 3,000 four-passenger vehicles — compared to the 14,000 taxis that currently operate in the city.
The algorithm would re-route vehicles as new requests for rides come in to take the most efficient routes, and send under-utilised vehicles to areas with higher demand. Riders would have an average wait-time of 2.7 minutes, it predicts.
If riders are prepared to go for minibus-style transportation rather than four-door cars, the gains could be even greater. 95% of demand is covered by 2,000 10-person vehicles, the study says.
"Instead of transporting people one at a time, drivers could transport two to four people at once, results in fewer trips, in less time, to make the same amount of money,” lead researcher Daniela Rus said in a statement. "A system like this could allow drivers to work shorter shifts, while also creating less traffic, cleaner air and shorter, less stressful commutes."
The findings are in line with previous studies: One from the OECD's International Transport Forum found that a fleet of eight-person and 16-person shared vehicles could theoretically cut the number of vehicles on the road by a whopping 97%.
It seems unlikely that any ride-hailing service would see the real-world efficiency gains described in these studies — or have the degree of market dominance required. There's also the problem of actually convincing people to use ride-sharing options: The motivation for some ride-hailing app users will be that they don't want to share with other strangers — otherwise they'd just use public transport.
But it still indicates the kind of improvements that smarter taxi apps can make to city streets — especially if people are prepared to swallow their pride and share.