CALIFORNIA: Harder to notice that a car drives by itself.

The car is a project of Google, which has been working in secret but inplain view on vehicles that can drive themselves, usingartificial-intelligence software that can sense anything near the carand mimic the decisions made by a human driver.

With someone behind the wheel to take control if something goes awayand a technician in the passenger seat to monitor the navigationsystem, seven test cars have driven 1,000 miles without humanintervention and more than 1,40,000 miles with only occasional humancontrol. One even drove itself down Lombard Street in San Francisco,one of the steepest and curviest streets in the nation. The onlyaccident, engineers said, was when one Google car was rear-ended whilestopped at a traffic light.

Robot drivers react faster than humans, have 360-degree perception anddo not get distracted, sleepy or intoxicated, the engineers argue. Theengineers say the technology could double the capacity of roads byallowing cars to drive more safely while closer together. Because therobot cars would eventually be less likely to crash, they could bebuilt lighter, reducing fuel consumption.

But of course, to be truly safer, the cars must be far more reliable.It drove at the speed limit, which it knew because the limit for everyroad is included in its database. The device atop the car produced adetailed map of the environment.

The car then drove in city traffic through Mountain View, stopping forlights and stop signs, as well as making announcements like“approaching a crosswalk” (to warn the human at the wheel) or “turnahead” in a pleasant female voice. This same pleasant voice would alertthe driver if a master control system detected anything amiss with thevarious sensors.