PALO ALTO, Calif. — Before the car can drive without a human, one must first get behind the wheel.

As the driver at this company accelerates, stops and turns on local streets, sensors on the car record what he sees and track how he responds. Then a team of engineers builds software that can learn how to behave from that data.

The software is installed in the car, and it can drive on its own. In the end, the car mimics choices made by the human driver.

This is how things work at Aurora Innovation, a start-up founded by three veterans of autonomous vehicle research, including Chris Urmson, who previously led the self-driving car project at Google.