Field-study data shows that African Americans wait longer to get rides and suffer more ride cancellations once drivers for transportation network companies (TNCs), or ride-sharing firms, determine they're black.

The new study — "Racial and Gender Discrimination in Transportation Network Companies," by researchers at the MIT Sloan School of Management, Stanford University and the University of Washington — relied on more than 1,400 individual cases of research assistants ordering, waiting and taking actual rides in Seattle and Boston with TNCs, primarily with Uber and Lyft. The controlled field experiments randomly selected times, days, routes and riders, some of whom were black, some white, and monitored various performance metrics at each stage of every trip.

In Seattle, one experiment found consistently longer waiting times for African American passengers — as much as a 35 percent increase.

In Boston, a separate experiment that captured a wider variety of performance metrics found more frequent cancellations against passengers when they used African American-sounding names. Across all trips, the cancellation rate for passengers using African American-sounding names was more than twice as frequent compared to when the same passengers used white sounding names.

Researchers say they were disappointed to find the existence of discrimination within the emerging TNC industry, considering many had hoped the new ride-sourcing phenomenon would serve as a break from the transportation industry's past history of racial discrimination.

"The patterns of discrimination were quite clear and consistent in both cities — and one can only assume it's happening all across the country in other markets," said Christopher R. Knittel, one of the study's authors and a professor at the MIT Sloan School of management. "The study has found major areas of racial discrimination within this new industry. It's quite concerning."

Researchers said there may be ways to correct at least some of the practices to reduce the impacts of discrimination, such as eliminating the practice of showing the names and photos of riders to drivers before orders are confirmed (as is the case at Lyft) or showing the names of riders once a driver accepts a ride order (as in the case of Uber).

"Though completely eliminating discrimination is likely impossible, there are steps TNCs can voluntarily take to minimize service bias against minorities," said Don MacKenzie, another of the study's authors and an assistant professor within the Department of Civil and Environmental Engineering at the University of Washington. "We hope TNC companies take positive steps to address these problems."

"The random field tests we conducted, with actual research assistants ordering and taking rides in two cities, are considered the 'gold standard' for tests measuring such human activities," said Stephen Zoepf, another of the study's authors and the executive director of the Stanford University Center for Automotive Research at Stanford University and a post-doctoral researcher at MIT. "We're very confident in, though disappointed by, the validity of the results we found."

The researchers are also quick to point out, however, that the discrimination they document among TNCs is not necessarily worse than the current taxi system. "In the Seattle experiment, we also document racial discrimination among conventional taxis, so we aren't taking a stand on which system is better or worse," said Knittel. "But, our study illustrates that discrimination among TNC drivers is occurring and we point to ways TNC companies can reduce this discrimination."