Google tests self-driving cars

Click on this link to read a Washington Post article (10-11-10) about cars that can steer, stop, and start without a driver.  The developers at Googel aren't seeking to replace the driver, but rather to have something that would step in to avoid accidents if the driver isn't paying attention.  Apparently the cars have already logged 140,000 miles on the California highways without serious incident.  Do you believe the move towards turning driving over to a machine is a good step?  Or are we inviting disaster?