Uber’s self-driving cars had to be taken over every mile by humans

Uber’s dream of a self-driving fleet of rideshare vehicles may be a bit further off than it once expected.

The ridesharing giant’s 43 self-driving cars drove a total of 20,354 miles autonomously during the week of March 6, according to internal testing data obtained by Recode. It’s an impressive — and steadily increasing — number for the company’s testing, around four times the amount of miles that Uber’s first 20 self-driving cars drove during testing in January.

It might not be all smooth sailing for the company’s testing, however. Uber’s self-driving cars still have human drivers in place to take over if need be, and those drivers had to do so much more often in recent testing than during testing in January. According to those internal documents, the drivers had to take over just about every mile for a variety of reasons — from navigation issues to missed turns, and even inclement weather snarling the system’s ability to work properly. Notably, Uber has yet to publicly announce these numbers.

It’s worth noting that these internal testing reports don’t include what Uber calls “critical interventions” — incidents that could have led to serious accidents. That number, thankfully for Uber, has been decreasing — with vehicles driving an average of 200 miles between critical interventions, compared to every 114 miles the week prior. That can be largely attributed to the fact that Uber’s proprietary self-driving systems are still learning.

Uber is currently testing its vehicles in three states: Pennsylvania, Arizona and California — although Uber has had trouble in the latter state. Uber’s testing might come to an abrupt end, however. A recent lawsuit filed by Google is asking for a stop to the firm’s self-driving car operations. The Mountain View tech giant is alleging that Otto, a self-driving trucking company owned by Uber, used stolen intellectual property from Google’s own autonomous vehicle project, Waymo.