Autonomous cars are better than regular cars for quite a few reasons, for example…

CO2 Emissions
Autonomous cars would be electric not combustion powered. For this reason, autonomous cars will be far more reliable and better for the economy and community and getting rid of CO2 emissions.

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Reaction Time
Humans have slow reaction times. A computer however can see and obstacle and make a best decision based on probability of survival and react almost instantly.

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Best Option
They have software that best indicates the best probability of survival like what objects to strike to stop the car and how to keep the passengers out of harm.