The jury is still out on whether ride-hailing services put more or fewer cars on the road. But according to a working paper published by the National Bureau of Economics, UberX drivers may be about 30 percent more efficient than taxi drivers when it comes to actually driving passengers—which could have implications on congestion for the rest of us.
Judd Cramer, a PhD candidate in economics at Princeton University, and Alan B. Krueger, the prominent Princeton economist (who, notably, co-authored a paper with Uber last year, but maintains no ongoing relationship) analyzed the efficiency of taxi drivers and UberX drivers in Boston, Los Angeles, New York, San Francisco and Seattle, using what they call “capacity utilization rate.” This is measured by either the amount of time, or number of miles, that a driver logs with a passenger in the car relative to total hours and mileage.
The data assembled was pretty scattershot. The statistics concerning UberX drivers in all five cities came from Uber covering the year 2015. But for taxi drivers, there was no single source of data. Depending on the city, statistics came from taxi commissions, DOTs, transportation researchers, and other sources. The time periods for which the taxi data was available didn’t always align with the Uber data. It’s also important to realize that, in thinking about time and mileage, UberX drivers aren’t restricted to certain jurisdictions as taxi drivers are—so the geographical scope of the drivers (potentially reflected in their time and mileage) isn’t the same.
But in cities where comparable data was available, they found significant differences in how Uber and taxi drivers spend their time and miles. On average, UberX drivers had a passenger in their car around half the time they were working, while taxi drivers had a passenger in their car anywhere from 32 percent of the time in Boston to nearly half the time in New York (which was the only city where taxi drivers were about as efficient, perhaps due to the city’s high density). In terms of miles, a similar story emerged. For example, the authors write:
In Los Angeles, taxi drivers have a passenger in the car for 40.7 percent of the miles they drive, while UberX drivers have a passenger in the car for 64.2 percent of their miles, resulting in a 58 percent higher capacity utilization rate for UberX drivers. In Seattle, UberX drivers achieve a 41 percent higher capacity utilization rate than taxis in terms of share of miles driven with a passenger in the car.
Perhaps it’s not surprising that Uber achieves greater driver efficiency than do taxi companies, with its app that matches drivers to passengers, its flexible labor supply and pricing structures, and its extremely large scale. Taxi companies, meanwhile, have licensing requirements that can constrain their ability to meet demand, and largely rely on a model developed in the 1940s. Krueger and Cramer’s findings add to the conclusion that, if the taxi industry wants to keep up with the Ubers of the world, it had better refresh its approach to technology.
What’s most useful about this study, though, is what it suggests about what taxi drivers are doing with all that excess time on the road. (No, they’re not shaving or calling into radio shows.) The authors write:
For example, for every mile that taxi drivers in Los Angeles drives with a passenger in the car, they drive 1.46 miles without a passenger; the comparable figure for UberX drivers is 0.56 mile. This difference likely translates to greater traffic congestion and wasteful fuel consumption.
The comparison opens a slice of new territory in the debate over ride-hailing’s impact on driving. If Uber trips are displacing an equivalent number of taxi trips, and if Uber serves the same kinds of trips that taxis do (which it doesn’t always—for example, Uber pick-ups aren’t allowed at many airports), then Uber could help lower congestion in some cities, says Susan Shaheen, the co-director of the Transportation Sustainability Research Center of the Institute of Transportation Studies at the University of California, Berkeley. “But if Uber trips are in addition to existing taxi trips, then the impact is less clear,” she tells CityLab. “These and similar questions definitely motivate the important and challenging analysis undertaken by Krueger and Cramer."
More research, with much better data, is badly needed. Hopefully, as both Uber and Lyft partner with cities to quantify their effects on the number of cars on the road, transportation officials will include their own analyses of taxi efficiency.