That’s according to Bryan Salesky, the CEO of the self-driving car company Argo AI, which became a Ford Motor subsidiary after the auto giant said in February it would invest $1 billion in the startup.

The rise of self-driving cars will usher a “much safer mode of transportation” by “removing the human from the loop,” Salesky said on Wednesday at the Rutberg FM technology conference in Half Moon Bay, Calif. Human drivers are more prone to distractions and errors in their judgment compared to autonomous cars in the future, Salesky believes.

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Salesky, who was once Google’s (GOOG) director of hardware for its self-driving car project, also believes that cities will have less need for parking spaces, which he said currently account for one-third of the space in an average urban city center. Self-driving cars would be constantly shipping people around cities instead of remaining parked for hours, and the unused parking spaces could be converted into office buildings or public parks, he explained.

People who buy self-driving cars will also have the option to convert their automobiles into autonomous taxis when they don’t use them, Salesky predicted. His thoughts echo recent statements made by Tesla (TSLA) CEO Elon Musk and Andrew Ng, the former head of AI for Chinese search giant Baidu, which is also working on self-driving cars.

Ford, which recently replaced CEO Mark Fields with Jim Hackett, is hoping new technologies like self-driving cars can help revive the struggling company. Fields said in January that Ford planned to develop a completely autonomous vehicle by 2021, and Salesky confirmed that the auto company is sticking with that date.

But Ford has a lot of work to do to improve autonomous vehicle technology, Salesky admitted, especially in terms of creating autonomous cars that can perceive nuances like the differences between children by themselves and when they are holding their mother’s hands. A self-driving car needs to know that children, when not by the side of their parents, may move “erratically,” and so the car must “then plan accordingly.” Self driving cars will need this ability to perceive tremendous amounts of detail on the road if they are to become mainstream.

Salesky says that advances in computing technology will make it possible for researchers to improve the machine learning algorithms powering self-driving cars, thus helping those cars better “see” the physical world by 2021.

The CEO did not directly compare Ford’s efforts on self-driving cars with competitors like Google’s Waymo unit, Tesla, or ride-sharing company Uber. But, he warned outsiders to be wary when these companies share statistics about how many miles their self-driving cars have driven.

Tesla, for example, said in December that Tesla cars with some self-driving capabilities have driven about 1.3 billion miles. Businesses brag about the number of miles their self-driving cars log because it’s “one of the few metrics the companies are forced to release” by regulators, he said.

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“Not all miles are the same, and that’s not the only indicator of success,” Salesky said.

He explained that miles logged by self-driving cars on the highway are not as valuable to researchers as miles driven in urban environments, because city driving involves more unpredictable variables like people suddenly crossing streets. This unpredictability can be used to help researchers create more powerful self-driving cars that can handle all driving situations, not just highway roads, which are “a much friendlier environment.”