The self-driving cars of Uber are still far from being safe enough to be deployed without human drivers, according to internal reports of the ride-hailing service.

While Uber's self-driving program is making progress, it is still far from being the business that would be able to massively drive up the company's profits.

Uber Self-Driving Program Metrics

The internal documents acquired by Recode provides the first glimpse into the progress being made by Uber's self-driving team in its testing program in Pennsylvania, Arizona, and California.

Compared to January, Uber's self-driving cars are traveling longer distances in March. The distance that Uber's vehicles drove autonomously in the first week of January was only 5,000 miles, but last week, the vehicles traveled 20,354 miles. Passengers in Pittsburgh took about 930 rides in self-driving cars last week, with passengers in Phoenix taking about 150 such rides.

Uber has been ramping up the number of self-driving vehicles it has on the road and the number of rides using these vehicles, which are operating with a pair of technicians in the front seats, one of which is behind the wheel and takes control of the vehicles when necessary.

The number of cases that human drivers had to take over of the self-driving vehicles, termed by Uber as disengagement, is still at a high number. For the week of March 8, when dividing the total number of miles driven by the vehicles by the number of times that the driver needed to take over, it was seen that the human driver had to take control once every 0.8 miles, which is far from an ideal figure.

Uber also measures the number of so-called critical interventions, which are the cases when the driver had to take over to prevent accidents. Last week, there was an average of 196 miles in between such cases, but it was 115 miles in the previous week and 160 miles before that, so the progress made by Uber's self-driving program in this area is still sporadic.

Lastly, there is also the measurement of bad experiences by passengers, which includes things such as abrupt jerking of the vehicles and sudden braking. The figure stood at 1.9 miles in between such experiences last week, compared to 4.5 miles at the beginning of January, which means that the rider experience in the self-driving cars have actually gotten worse.

Uber Self-Driving Cars Not Yet Ready

Bryant Walker Smith, a member of the Advisory Committee on Automation in Transportation that was set up by the U.S. Department of Transportation, told BuzzFeed that to be able to deploy self-driving vehicles without human drivers, Uber will need to come up with metrics that are far better than what have been reported.

However, it is still early on in Uber's testing of its self-driving vehicles, which means that there is still much progress to be made.

It should be noted though that improving these metrics will not be the only thing that would hold back Uber's self-driving vehicles. Alphabet's self-driving unit Waymo has accused Uber of stealing self-driving technology, with a lawsuit already filed against the ride-hailing company. This is also just one of the many controversies that Uber is currently embroiled in, so the company has its work cut out for it to stay afloat.