Uber drivers may be discriminating against African-American travelers, a joint study between researchers from Stanford, MIT and the University of Washington suggests.

The research, according to a Stanford News article, revealed that African-American travelers are more likely to wait longer for their rides to be accepted, to wait longer for their rides to arrive and to have their rides cancelled by drivers.

Conducted in two parts, the study recorded around 1,500 trips in total.

The first part took place in Seattle, where University of Washington researchers recorded 581 trips between eight research assistants hailing rides from various spots in the city. The assistants included two white women, two white men, two African-American women and two African-American men.

At the conclusion of the first stage of of the study, the African-American riders waited on average 20 percent longer to have their UberX rides accepted than their white counterparts. The African-American riders also waited approximately 30 percent longer to be picked up. For the same trial with Lyft rides, African-American riders experienced the same increased wait time for ride acceptance with no significant difference in pick-up time.

The study’s second part was carried out in Boston by Stephen Zoepf, the executive director of the Center for Automotive Research at Stanford. The riders in this leg of the study included people who could pass for either white or African-American. Each participant was given two different rider profiles by researchers: one with a stereotypically African-American name and one with a stereotypically white name.

The UberX rides of travelers whose profiles were attached to African-American names were cancelled twice as many times as those attached to white names. In areas with low population density, rides were cancelled three times as often.

Lyft drivers showed no difference in ride cancellation rate between the two sets of profiles, which researchers attributed to a slight difference in the two applications. Lyft, unlike Uber, shows its drivers the name of a passenger as soon as a ride is available. The Uber app only allows its drivers to view the name of their riders after they have accepted a ride.

This difference in how each ride-share app works may be indicative of how ride-share companies can alter their services to prevent discrimination. The researchers suggest “including using a passcode to identify passengers instead of a name, more severe consequences for cancellations (including situations where drivers sit in place to prompt the traveler to cancel), [or] audits from outside partners to analyze driver behavior.”

Contact Edan Armas at edaarmas ‘at’ stanford.edu.