By the Numbers: 700,000

With brazen jaywalkers, cars lurching out of hidden alleys, meandering cyclists and endless stop-and-go intersections, city streets can be some of the most complicated routes for a driver to navigate. That’s why Google has directed its fleet of driverless cars from the freeway to the city to master the chaos. To date, the self-driving vehicles have logged 700,000 autonomous miles on Silicon Valley roadways. Turns out, what seems random to the human brain is pretty predictable to a computer-controlled car, even construction zones and scofflaw pedestrians. The search giant has tweaked its car-operating software to accommodate thousands of situations, from the routine (like stopping at a red light) to the one-off (zipping right past it). The hard part will be convincing the general public to relinquish its freedom to bend the rules to a well-behaved, speed limit-abiding robot car.