Big problem with Google cars...

...They obey all the traffic laws.

One Google car, in a test in 2009, couldn't get through a four-way stop because its sensors kept waiting for other (human) drivers to stop completely and let it go. The human drivers kept inching forward, looking for the advantage — paralyzing Google's robot.

The idea of a self-driving car appeals to me a lot. But the four way stop on my daily commute, where some drivers are intent on not taking their turns, show me why the obedience of self-driving prototypes present them with obstacles.