Self-driving car tests conducted by Uber saw vehicles requiring manual overrides every mile, according to a leaked report.
Internal documents obtained by technology news website Recode revealed the progress of Uber’s self-driving fleets in Arizona, California and Pennsylvania.
The key metric—miles per intervention—was just 0.8 miles at its latest measure, taken from the week of March 8. The figure took into account 20,354 miles driven by 43 of Uber’s self-driving cars.
These human interventions could be a result of anything from overshooting a turn, to incorrectly navigating unclear lane markings. For critical interventions, meaning when a driver has to take over to avoid harmful events, cars averaged 200 miles between incidents.
This was an improvement from the previous week, which recorded an average of 114 miles between critical interventions.
Uber did not immediately respond to a request for comment.
Beyond self-driving cars, Uber has long-term ambitions to develop a fleet of autonomous flying vehicles.
In February, former NASA engineer Mark Moore joined the ride-hailing firm as director of engineering for aviation of Uber Elevate.
The Elevate network was described in a 99-page white paper published in 2016 by Jeff Holden, Uber’s chief product officer.
“Recently, technology advances have made it practical to build this new class of VTOL (vertical takeoff and landing) aircraft,” Holden’s paper stated. “Over a dozen companies, with as many different design approaches, are passionately working to make VTOLs a reality.”