The Atlantic writes about Google’s trick to make its self-driving cars work.

“We tell it how high the traffic signals are off the ground, the exact position of the curbs, so the car knows where not to drive,” he said. “We’d also include information that you can’t even see like implied speed limits.”

Google has created a virtual world out of the streets their engineers have driven. They pre-load the data for the route into the car’s memory before it sets off, so that as it drives, the software knows what to expect.

Although Google is not wrong to call them self-driving cars, these car are still not true self-driving cars. They can only work on streets that Google has mapped out. This means that Google will need to recreate a virtual version of every street that the cars will operate on. Google might be able to achieve such a task but it is still a staggering job.