Sources: Official Google Blog, Google+
quote: An initial 100 testbed versions would retain manual controls, Google said as it unveiled the car on Tuesday. The controls are needed to comply with the law in California which along with Nevada and Florida allows autonomous vehicles but only if a driver can take charge.
quote: No more dirty cabbies.
quote: Because that's why it's a prototype at this point, because the computer is expected to screw up sometimes; or maybe it's already smart enough to know when it screws up and just stop when that happens.