system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is gps for self-driving cars accurate enough when my google gps totally craps out any time I'm in a mall plaza?
gpt
Self-driving cars use more than just GPS to navigate; they also use onboard cameras to identify the road, other vehicles, pedestrians, traffic lights, and other potentially relevant information. If they lose GPS signal, they continue going along what was the plotted route until the signal is regained. 

As the technology improves, they can also gather data on *where* GPS is likely to fail (such as a tunnel or mall plaza). In these instances, their navigation can plot more detailed courses in advance since the computer is anticipating a loss of satellite feed for a bit.