The steering wheel is a legal requirement, but Google’s plan is to take the driver out of driving completely.

Earlier this year, during a presentation at the South by Southwest festival in Austin, Astro Teller, head of the Google X research division that created the self-driving car, said that in autumn 2012 the company started allowing Google employees to take the Lexus version home and self-drive on the freeway, so long as they kept paying attention in the event of an emergency.

Despite this, the employees got used to self-driving and stopped paying attention.

“The assumption that humans can be a reliable backup for the system was a total fallacy,” Mr. Teller said in the presentation. “Once people trust the system, they trust it.” Google realized the best thing to do “was to make a car that has no steering wheel, that has no brake pedal, that has no acceleration pedal — that drives itself all the time, from point A to point B, at the push of a button.”

Of course, nothing is accident-proof. Earlier this week, Chris Urmson, director of Google’s Self-Driving Car Project, disclosed that self-driving cars had been in 11 “minor accidents” in which there was only light damage and no injuries, and that “not once was the self-driving car the cause of the accident.”

This included seven rear-end collisions, a couple of wrecks in which cars were sideswiped and one crash in which the self-driving car was hit by a driver who rolled through a stop sign.

The challenge of city driving is one reason driverless technology has first arrived on highways. In the coming months, Tesla Motors has promised to introduce an “autopilot” feature that can take over highway driving in certain conditions. Next year, other automakers will do the same, such as General Motors’ “Super Cruise,” which will allow hands-off-the-wheel, foot-off-the-pedals highway driving.