Uber launched its second pilot program in San Francisco last week, but the day it launched, a car ran straight through a red light.

Uber has since said the incident was due to human error, but it's not clear whether that means a person drove through the light or failed to stop the car from doing so while it was in autonomous mode. Either way, Uber knows its cars will fail from time-to-time, which is why a safety driver and engineer sit upfront while the cars autonomously drive people.

(Uber shut down the San Francisco pilot program on Wednesday after the California DMV revoked the cars' registration.)

Uber let us get behind the wheel for the launch of its pilot program in Pittsburgh in September, and we got to see firsthand what it's like when the car fails and needs a driver to take over.

Keep in mind that Uber used self-driving Volvo XC90s for the San Francisco pilot instead of the self-driving Ford Fusions in Pittsburgh. As a result, the interface we experienced is slightly different from the one in the Volvo cars.

But you can scroll down to get a basic sense of what it's like when the robot cars need help: